opentf/website/docs/cli/commands/test/examples/provider_alias/main.tf

terraform {
  required_providers {
    docker = {
      source  = "kreuzwerker/docker"
      version = "3.0.2"
    }
  }
}

resource "docker_image" "build" {
  name = "myapp"
  build {
    context = "."
  }
}