Also it works with private repos too if you provide a personal access token (fine-grained) in the Obtainium app settings. Just make sure to "release" (on the Releases tab) the .apk file on the GitHub repo and tag it latest.
I use 'just' (command runner) and the 'gh' CLI to automate this:
I use 'just' (command runner) and the 'gh' CLI to automate this: