How to set AWS_REGION with orbs?

I am trying to use orbs for the first time. I’m trying to use the circleci aws-ecr and aws-ecs to build a docker image, upload it to ECR then deploy it to ECS.

I’ve reduced my config.yml to that ORB example for “build_and_push_image”. When I run it, the first thing it does is try to set the region with “aws configure”. Where in the circle-ci can I define the region?

Can I define it in the workflow? Can I make a job or executor and define it there? I’m guessing I can assign it in the project settings but I’d like to keep it as a variable.

I can’t find a working example of using the aws-ecr orb.

Any pointers?