My local laptop is a Mac.
The ssh key is configured properly. This is the content of ~/.ssh/config
Host barthea
Hostname git-codecommit.us-east
I also face same 403 error while using git push command in windows. I done all settings mentioned in AWS docs, but non resolved my issue. After i reviewed git credential set via Windows Credential as shown in screen. I found instead of git https credentials, it set access key / secret key (don't know how).
Click on edit link, update credential with proper git credential generated for AWS User, everything worked fine.