You can store your software in the Remository file store. Access can be controlled by setting the groups that can access a container. Remository provides a module to show users their ID string needed to enable updates. The Remository multi-module can help you to construct the download link for the XML. More details can be found at https://docs.black-sheep-research.com/remository:joomlaupdate.
Support Services
Please consider looking at the Remository documentation to see if it answers your question. Or search the question and answer section here. If you are unable to solve your problem that way, please raise a support ticket. Subscribers have priority support - usually a response within one working day. Tickets from others may receive limited attention. You can also raise a support ticket by emailing support@remository.com.
