The return hash contains a role field which refers to the Organization Invitation role and will be one of the following values: direct_member, admin, billing_manager, hiring_manager, or reinstate. If the invitee is not a GitHub member, the login field in the return hash will be null.

Note: You can also specify a team by org_id and team_id using the route GET /organizations/{org_id}/team/{team_id}/invitations.
List pending team invitations