Would you consider packaging releases in a way that supports WoW Up? You should be able to do it via GitHub.

Sadly, I'm lacking the ability to articulate how. I see that you have releases here but I'm not sure what the difference is. An example that works is HHTD.

https://github.com/2072/H-H-T-D

Also, I appreciate you making your work part of the public domain.

I figured it out. Here's the YML I used: https://github.com/szjunklol/MBB/blob/master/.github/workflows/main2.yml

How did you use it on WoWup? can you explain? :)

Sure. WoW Up has an option called Install from URL. If you use the github action, it packages it in a way that WoW Up can understand when it's imported.

Get Addons > Install from URL

You should get a pop up then paste https://github.com/szjunklol/MBB and click import.

Then it should preview the addon. In my case, the addon is out of date so it gave me a warning.

After adding the action, you do need to create a new release tag. I believe what WoW Up does is parse the release JSON:
{"releases":[{"name":"MinimapButtonBag","version":"90005","filename":"MBB-90005.zip","nolib":false,"metadata":[{"flavor":"mainline","interface":90005}]}]}

That tells it what version of the game the addon is available for and what zip file to use.

The Ajour addon manager also benefits from this. It also has the "Install from URL" feature. https://github.com/ajour/ajour/

AdiBags can also be installed by 3rd party addon managers. Check out their project here to see how they do it. https://github.com/AdiAddons/AdiBags