Error deploying ECS with EC2

I’m following the example “ECS with ALB example” from the official Hashicorp repo to deploy an ECS service with a connected EC2 instance.

Running this example as is (without any changes), the ECS service is created, as is the EC2 instance. However, they are not ‘connected’, therefore the service can’t deploy the task.

I’m running this on eu-west-1