docker login

$ docker pull container-registry.oracle.com/database/enterprise:21.3.0.0
Error response from daemon: Head "https://container-registry.oracle.com/v2/database/enterprise/manifests/21.3.0.0": unauthorized: authentication required

$ docker login container-registry.oracle.com
Username: me@here.xyz 
Password: …
WARNING! Your password will be stored unencrypted in /home/rene/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store