Outside of the required_providers block, Terraform configurations always refer to providers by their local names.

Outside of the required_providers block, Terraform configurations can refer to providers by either their local names or their source addresses. The local name is a short name that can be used throughout the configuration, while the source address is a global identifier for the provider in the format registry.terraform.io/namespace/type. For example, you can use either aws or registry.terraform.io/hashicorp/aws to refer to the AWS provider.