I found the docker build workflow in the registry (was good to see CP pop up there when searching).
I get this log when using it, though. Is this a familiar error?
Retrieving registries data through AWS SDK...
AWS ECR detected with us-east-1 region
Logging into https://123456789.dkr.ecr.us-east-1.amazonaws.com...
Error: Error saving credentials: error storing credentials - err: exit status 1, out: not implemented