{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "newStorageAccountNamePrefix": {
      "value": ""
    },

    "vmNamePrefix": {
      "value": ""
    },

    "dnsPrefix": {
      "value": ""
    },
    "location": {
      "value": "West Europe"
    },
    "adminPassword": {
      "value": ""
    },
    "sqlServerServiceAccountPassword": {
      "value": ""
    }
  }
}

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "newStorageAccountNamePrefix": {
      "value": ""
    },

    "vmNamePrefix": {
      "value": ""
    },

     "domainName": {
      "value": ""
    },

    "dnsPrefix": {
      "value": ""
    },
    "location": {
      "value": "West Europe"
    },
    "adminPassword": {
      "value": ""
    },
    "sqlServerServiceAccountPassword": {
      "value": ""
    }
  }
}

Add domainName into parameter file
Add domainName into parameter file
