Exam AWS Certified Security - Specialty topic 1 question 448 discussion

Authentication requests are tied to specific regions, and cannot be used across regions. To resolve the issue, ensure that you have retrieved an authentication token from the same Region your repository exists in. https://docs.aws.amazon.com/AmazonECR/latest/userguide/common-errors-docker.html#error-403

HTTP 403 Errors or "no basic auth credentials" error when pushing to repository There are times when you may receive an HTTP 403 (Forbidden) error, or the error message no basic auth credentials from the docker push or docker pull commands, even if you have successfully authenticated to Docker using the aws ecr get-login-password command. The following are some known causes of this issue: You have authenticated to a different region Authentication requests are tied to specific regions, and cannot be used across regions. For example, if you obtain an authorization token from US West (Oregon), you cannot use it to authenticate against your repositories in US East (N. Virginia). To resolve the issue, ensure that you have retrieved an authentication token from the same Region your repository exists in. For more information, see Private registry authentication.

https://docs.aws.amazon.com/AmazonECR/latest/userguide/common-errors-docker.html#error-403