Do not push any code to that repository.

1. On https://github.com/nextcloud, tag appropriate commit on the source repository
2. Push the new tag to this repository
3. Create release on this repository

1. Make sure you have the necessary workflow on your https://github.com/nextcloud source repository
2. Make sure your tagged commit also have the workflow
3. Make sure this repository have the proper APP_PRIVATE_KEY secret set
4. Make the nextcloud_release_service user is a co-maintainer of your app on https://apps.nextcloud.com/
5. Make sure you have admin rights to this repository