By default, issues cannot be deleted in an organization's repositories. An organization owner must enable this feature for all of the organization's repositories first.
Once enabled, organization owners and people with admin access in an organization-owned repository can delete issues. People with admin access in a repository include organization members and outside collaborators who were given admin access. For more information, see Repository roles for an organization and Deleting an issue.
- In the upper-right corner of GitHub, select your profile photo, then click Your organizations**.
- Next to the organization, click Settings.
- In the "Access" section of the sidebar, click Member privileges.
- Under "Issue deletion", select Allow members to delete issues for this organization.
- Click Save.