Merge pull request #4 from TomArcherMsft/patch-3

Update creation-terraform.md

Author: LiSeda

articles/app-service/environment/creation-terraform.md

@@ -65,12 +65,16 @@ In a host group deployment, your apps are deployed onto a dedicated host group.
 
 With a dedicated host group deployment, there are a finite number of cores available that are used by both the App Service plans and the infrastructure roles. This type of deployment can't reach the 200 total instance count normally available in App Service Environment. The number of total instances possible is related to the total number of App Service plan instances, plus the load-based number of infrastructure roles.
 
+> [!IMPORTANT]
+> If you're using the 4.x azurerm provider, you must [explicitly specify the Azure subscription ID](https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/guides/4.0-upgrade-guide#specifying-subscription-id-is-now-mandatory) to authenticate to Azure before running the Terraform commands.
+>
+> One way to specify the Azure subscription ID without putting it in the `providers` block is to specify the subscription ID in an environment variable named `ARM_SUBSCRIPTION_ID`.
+>
+> For more information, see the [Azure provider reference documentation](https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs#argument-reference).
+
 ## Implement the Terraform code
 
-> [!NOTE]
-> The sample code for this article is located in the [Azure Terraform GitHub repo](https://github.com/Azure/terraform/tree/master/quickstart/101-app-service-environment). You can view the log file containing the [test results from current and previous versions of Terraform](https://github.com/Azure/terraform/tree/master/quickstart/101-app-service-environment/TestRecord.md).
-> 
-> See more [articles and sample code showing how to use Terraform to manage Azure resources](/azure/terraform).
+The sample code for this article is located in the [Azure Terraform GitHub repo](https://github.com/Azure/terraform/tree/master/quickstart/101-app-service-environment). You can view the log file containing the [test results from current and previous versions of Terraform](https://github.com/Azure/terraform/tree/master/quickstart/101-app-service-environment/TestRecord.md). See more [articles and sample code showing how to use Terraform to manage Azure resources](/azure/terraform).
 
 1. Create a directory in which to test and run the sample Terraform code, and make it the current directory.