I've been using Obtainium instead and loaded Infinity through it this morning. You can also have it pull from f-droid repos instead of GitHub if you want when that hits
Edit: Currently the app is in prerelease so you'll need to toggle that option. Once they have a full release you can toggle it back off.
I paid for Sync to toss some money to a dev responsible for the #1 used app on any of my phones for the last 10 years. I paid a criminally low amount back then for how much I used the app.
It happened to also come with ad removal, but I block those and trackers on my network anyway.