**Objective:** How to access and assign object type variable value from terraform root config

**Code I am trying:**

I am using modules in terraform. The following is one module I am using to create a cosmos DB account

**child module:**

```
resource "azurerm_cosmosdb_account" "cosmosaccount" {
  name                = var.account_name
  location            = var.location
  resource_group_name = var.rg_name  
  offer_type          = var.cosmos_db_config.cosmosdb_offer_type
  kind                = var.cosmos_db_config.cosmosdb_kind
  is_virtual_network_filter_enabled = "true"
  ip_range_filter     = var.cosmos_db_config.ip_range_filter
  enable_automatic_failover = false
  consistency_policy {
    consistency_level       = var.cosmos_db_config.cosmosdb_consistancy_level
    max_interval_in_seconds = 5
    max_staleness_prefix    = 100
  }
  geo_location {
    location          = var.location
    failover_priority = 0
  }
  tags = var.tags
}

```

**child module variable.tf:**

```
variable "cosmos_db_config" {
  default = {
    cosmosdb_offer_type = ""
    cosmosdb_kind   = ""
    cosmosdb_consistancy_level = ""
    ip_range_filter = ""
  }
  type = object(
    {
    cosmosdb_offer_type = string
    cosmosdb_kind   = string
    cosmosdb_consistancy_level = string
    ip_range_filter = string
    }
  )
}

```

**main root variable.tf:**

```
variable "cosmos_db_config" {
  default = {
    cosmosdb_offer_type = ""
    cosmosdb_kind   = ""
    cosmosdb_consistancy_level = ""
    ip_range_filter = ""
  }
  type = object(
    {
    cosmosdb_offer_type = string
    cosmosdb_kind   = string
    cosmosdb_consistancy_level = string
    ip_range_filter = string
    }
  )
}

```

**Module call:**

```
module "cosmosdb" {  
  source = "../modules/cosmosdb"
  account_name = "test"
  rg_name  = module.resource_group.name
  location = module.resource_group.location
  cosmosdb_offer_type = var.cosmos_db_config.cosmosdb_offer_type
  cosmosdb_kind = var.cosmos_db_config.cosmosdb_kind
  ip_range_filter = var.cosmos_db_config.ip_range_filter
  #subnet_id = var.subnet_id
  cosmosdb_consistancy_level = var.cosmos_db_config.cosmosdb_consistancy_level
  tags = local.common_tags
}

```

**terraform.tfvars.json:**

```
"cosmos_db_config": {
        "cosmosdb_offer_type": "Standard",
        "cosmosdb_kind": "GlobalDocumentDB",
        "cosmosdb_consistancy_level": "Session",
        "ip_range_filter": ""
    },

```

**Error I get:**

```
Error: Unsupported argument
│ 
│   on cosmosdb.tf line 6, in module "cosmosdb":
│    6:   cosmosdb_offer_type = var.cosmos_db_config.cosmosdb_offer_type
│ 
│ An argument named "cosmosdb_offer_type" is not expected here

```

Can you please suggest what mistake I am doing here ?