Adding private addon repository

I’m working on a couple addons that I’ve been developing locally. Things are working just fine on that front, but I’ve gotten to the point where I want to create a proper repository so I can eventually open it up to the community. Until that time I’d rather the repository stay private, however, I’m running into some issues. I’m almost certain that I can only add a repository that goes over HTTPS as SSH URLs fail regardless of whether the repo is public or private.

Has anyone ever tried this and have any words of advice?