Can't access AWS CodeCommit with SSH
It looks like you missed a step in setting up SSH. You need to add this information to your .ssh/config file:
Host git-codecommit.us-east-1.amazonaws.com
User Your-SSH-Key-ID, such as APKAEIBAERJR2EXAMPLE
IdentityFile Your-Private-Key-File, such as ~/.ssh/codecommit_rsa or ~/.ssh/id_rsa
You can get Your-SSH-Key-ID from the IAM console.