Suggestion:
Add-ons have been renamed to Apps some months ago now.
Using the term Add-on with new software can cause some confusion because people have been trying to find add-on in the HA UI, and it is no longer there. Confusion = more issues for you to deal with.
(In your Git Repo this mo longer works: **add the repository manually: Settings → Add-ons → Add-on store **
Please consider a wording revision.