I'm trying to deploy a Function App using an ARM template and Params file into an existing but empty resource group. I'm getting the following error:

```
{
    "id": "/subscriptions/XXX",
    "operationId": "5D2F1EA84E184AF3",
    "properties": {
        "provisioningOperation": "Create",
        "provisioningState": "Failed",
        "timestamp": "2019-10-25T15:18:39.495039Z",
        "duration": "PT3.9855754S",
        "trackingId": "2bd91b5a-4655-4ad8-9d04-1ae7f10bfd20",
        "statusCode": "BadRequest",
        "statusMessage": {
            "Code": "BadRequest",
            "Message": "There was a conflict. The remote server returned an error: (403) Forbidden.",
            "Target": null,
            "Details": [{
                    "Message": "There was a conflict. The remote server returned an error: (403) Forbidden."
                }, {
                    "Code": "BadRequest"
                }, {
                    "ErrorEntity": {
                        "ExtendedCode": "01020",
                        "MessageTemplate": "There was a conflict. {0}",
                        "Parameters": ["The remote server returned an error: (403) Forbidden."],
                        "Code": "BadRequest",
                        "Message": "There was a conflict. The remote server returned an error: (403) Forbidden."
                    }
                }
            ],
            "Innererror": null
        },
        "targetResource": {
            "id": "/subscriptions/XXX/brw-func-dev-ce-to-avaloq2",
            "resourceType": "Microsoft.Web/sites",
            "resourceName": "brw-func-dev-ce-to-avaloq2"
        }
    }
}

```

My template file:

```
{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "location": {
      "type": "string",
      "defaultValue": "[resourceGroup().location]",
      "metadata": {
        "description": "Location for all resources."
      }
    },
    "siteName": {
      "defaultValue": "brw-func-dev-ce-to-avaloq",
      "type": "string"
    },
    "appServicePlan": {
      "defaultValue": "",
      "type": "string"
    },
    "appInsightsInstrumentationKey": {
      "defaultValue": "XXX",
      "type": "string"
    },
    "appInsightsName": {
      "defaultValue": "brw-appins-dev-ce-to-avaloq",
      "type": "string"
    },
    "storageAccountName": {
      "defaultValue": "brwstordevcdtoavaloq",
      "type": "string"
    },
    "azureWebJobsStorage": {
      "defaultValue": "DefaultEndpointsProtocol=https;AccountName=brwstordevcetoavaloq;AccountKey=XXX",
      "type": "string"
    },
    "mappingConfig": {
      "defaultValue": "Interfaces.Avaloq.Persistence.NewClient.Concrete.MappingConfigFixed, Interfaces.Avaloq.Persistence",
      "type": "string"
    },
    "newClientMappingService": {
      "defaultValue": "Interfaces.Avaloq.Persistence.NewClient.Concrete.NewClientMappingService, Interfaces.Avaloq.Persistence",
      "type": "string"
    },
    "newClientService": {
      "defaultValue": "Interfaces.Avaloq.Persistence.NewClient.Concrete.NewClientService, Interfaces.Avaloq.Persistence",
      "type": "string"
    },
    "referenceDataService": {
      "defaultValue": "Interfaces.Avaloq.Infrastructure.ReferenceData.Concrete.ApiReferenceDataService, Interfaces.Avaloq.Infrastructure",
      "type": "string"
    },
    "referenceDataServiceApiIsCachingEnabled": {
      "defaultValue": "false",
      "type": "string"
    },
    "serviceBusConnection": {
      "defaultValue": "XXX",
      "type": "string"
    },
    "pipelineProcessingRequestValidationEnabled": {
      "defaultValue": "true",
      "type": "string"
    },
    "pipelineProcessingPerformanceBehaviourEnabled": {
      "defaultValue": "true",
      "type": "string"
    },
    "referenceDataServiceApiBaseAddress": {
      "defaultValue": "XXX",
      "type": "string"
    },
    "referenceDataServiceApiSubscriptionKey": {
      "defaultValue": "XXX",
      "type": "string"
    },
    "referenceDataServiceApiCacheProviderServiceTypeName": {
      "defaultValue": "",
      "type": "string"
    },
    "avaloqClientApiBaseAddress": {
      "defaultValue": "XXX",
      "type": "string"
    },
    "avaloqClientApiBearerToken": {
      "defaultValue": "XXX",
      "type": "string"
    }

  },
  "variables": {
  },
  "resources": [
    {
      "apiVersion": "2015-05-01",
      "name": "[parameters('appInsightsName')]",
      "type": "microsoft.insights/components",
      "location": "[parameters('location')]",
      "tags": {
      },
      "properties": {
        "ApplicationId": "[parameters('appInsightsName')]",
        "Request_Source": "IbizaWebAppExtensionCreate"
      }
    },
    {
      "apiVersion": "2019-06-01",
      "type": "Microsoft.Storage/storageAccounts",
      "name": "[parameters('storageAccountName')]",
      "location": "[parameters('location')]",
      "sku": {
        "name": "Standard_LRS",
        "tier": "Standard"
      },
      "kind": "Storage",
      "properties": {
                "networkAcls": {
                    "bypass": "AzureServices",
                    "virtualNetworkRules": [],
                    "ipRules": [],
                    "defaultAction": "Allow"
                },
                "supportsHttpsTrafficOnly": false,
                "encryption": {
                    "services": {
                        "file": {
                            "enabled": true
                        },
                        "blob": {
                            "enabled": true
                        }
                    },
                    "keySource": "Microsoft.Storage"
                }
      }
    },
    {
      "type": "Microsoft.Web/serverfarms",
      "apiVersion": "2018-02-01",
      "name": "[parameters('appServicePlan')]",
      "location": "West Europe",
      "sku": {
        "name": "Y1",
        "tier": "Dynamic"
      },
      "properties": {
        "name": "[parameters('appServicePlan')]",
        "computeMode": "Dynamic"
      }
    },
    {
      "type": "Microsoft.Web/sites",
      "apiVersion": "2016-08-01",
      "name": "[parameters('siteName')]",
      "location": "[parameters('location')]",
      "kind": "functionapp",
      "dependsOn": [
        "[resourceId('Microsoft.Web/serverfarms', parameters('appServicePlan'))]",
        "[concat('microsoft.insights/components/', parameters('appInsightsName'))]",
        "[concat('Microsoft.Storage/storageAccounts/', parameters('storageAccountName'))]"
      ],
      "properties": {
        "name": "[parameters('siteName')]",
        "serverFarmId": "[parameters('appServicePlan')]",
        "hostingEnvironment": "",
        "clientAffinityEnabled": false,
        "siteConfig": {
          "appSettings": [
            {
              "name": "AzureWebJobsDashboard",
              "value": "[parameters('azureWebJobsStorage')]"
            },
            {
              "name": "AzureWebJobsStorage",
              "value": "[parameters('azureWebJobsStorage')]"
            },
            {
              "name": "MappingConfig",
              "value": "[parameters('mappingConfig')]"
            },
            {
              "name": "NewClientMappingService",
              "value": "[parameters('newClientMappingService')]"
            },
            {
              "name": "NewClientService",
              "value": "[parameters('newClientService')]"
            },
            {
              "name": "ReferenceDataService",
              "value": "[parameters('referenceDataService')]"
            },
            {
              "name": "ReferenceDataServiceApiIsCachingEnabled",
              "value": "[parameters('referenceDataServiceApiIsCachingEnabled')]"
            },
            {
              "name": "FUNCTIONS_EXTENSION_VERSION",
              "value": "~2"
            },
            {
              "name": "WEBSITE_NODE_DEFAULT_VERSION",
              "value": "10.14.1"
            },
            {
              "name": "APPINSIGHTS_INSTRUMENTATIONKEY",
              "value": "[parameters('appInsightsInstrumentationKey')]"
            },
            {
              "name": "FUNCTIONS_WORKER_RUNTIME",
              "value": "dotnet"
            },
            {
              "name": "ServiceBusConnection",
              "value": "[parameters('serviceBusConnection')]"
            },
            {
              "name": "WEBSITE_CONTENTAZUREFILECONNECTIONSTRING",
              "value": "[parameters('azureWebJobsStorage')]"
            },
            {
              "name": "WEBSITE_CONTENTSHARE",
              "value": "[parameters('siteName')]"
            },
            {
              "name": "PipelineProcessingPerformanceBehaviourEnabled",
              "value": "[parameters('pipelineProcessingPerformanceBehaviourEnabled')]"
            },
            {
              "name": "PipelineProcessingRequestValidationEnabled",
              "value": "[parameters('pipelineProcessingRequestValidationEnabled')]"
            },
            {
              "name": "ReferenceDataServiceApiBaseAddress",
              "value": "[parameters('referenceDataServiceApiBaseAddress')]"
            },
            {
              "name": "ReferenceDataServiceApiSubscriptionKey",
              "value": "[parameters('referenceDataServiceApiSubscriptionKey')]"
            },
            {
              "name": "ReferenceDataServiceApiCacheProviderServiceTypeName",
              "value": "[parameters('referenceDataServiceApiCacheProviderServiceTypeName')]"
            },
            {
              "name": "AvaloqClientApiBaseAddress",
              "value": "[parameters('avaloqClientApiBaseAddress')]"
            },
            {
              "name": "AvaloqClientApiBearerToken",
              "value": "[parameters('avaloqClientApiBearerToken')]"
            }
          ]
        }
      }
    }
  ]
}

```

Any ideas what could be causing the error please?