Add a new contact to a group

I have a contact group - sorry if this is the wrong terminology - and want to add another contact to that group. I can’t figure out how to do this but I’m sure it must be possible and probably simple. Can anyone help me do this?
Thanks!!

Click on CONTACTS, find your Group entry and click to open it, click on +Add Member

Thank you very much! I found it under the EDIT tab. Thanks for the hint!

Glad to be of assistance.