Not able to add new collaborator

Hi Chiefs
I’ve installed Gitea on my server to manage one of the project that I am working on. I am new to Gitea. I am trying to add team members and I got a message “The user does not exist”. Enclosed is the screen shot.

Will greatly appreciate if you one of you can guide me in adding team members.

You have to add a user account for them on the Gitea server first, then you can add the username of that account to the repository. Check under “Site Administration” to add a user account to the site.