Must be an a GitHub Admin for organization that owns Private or Public repository.
By default GitHub restricts third-party applications to access Company Owned applications - see https://help.github.com/articles/about-third-party-application-restrictions.
Verify if your organization has granted access to 3rd party applications to access your repositories:
- Go to https://github.com/settings/connections/applications/4194d7d196308e89f706
- Click 'Grant Access' under Organization access (if button is not visible then org admin must do this step)
You will now be able to see organization repos on Add Repository page.