Assigning issues and pull requests to other GitHub users
Assignees clarify who is working on specific issues and pull requests.
Anyone with write permissions to a repository can assign issues and pull requests.
You can assign up to 10 people to each issue or pull request, including yourself, anyone who has commented on the issue or pull request, anyone with write permissions to the repository, and organization members with read permissions to the repository. For more information, see "Access permissions on GitHub."
On GitHub, navigate to the main page of the repository.
Under your repository name, click Issues or Pull requests.
Select the checkbox next to the items you want to assign to someone.
In the upper-right corner, click Assignee.
To assign the items to a user, start typing their username, then click their name when it appears. You can select and add up to ten assignees to an issue or pull request.