To invite a new collaborator to your repo in GitHub, follow the steps below:
- Go to the repo in GitHub
- Click the Settings tab at the top
3. Click the Collaborators tab on the side
4. Type in the team member's name/username/email address to find them. Click the "Add collaborator" button
Once you've done this, the new member you have invited will receive an email from GitHub with an invitation to join the repo.