I had a quick test on Lab1-4 (lab start intro-prepare) with copying and pasting the commands from course material, but there is no issue at all with downloading my execution environment image as attached.
If you are very certain that you follow the steps in the course material but the issue is still persisting, you might want to raise a support ticket. The "podman pull" command should be performed on Lab1-4 if the authentication was successful with the automation hub.
