Found the issue, published a new build, added a few features, and tested on a few devices now that I'm back home. Should be fully operational for you now!
I am updating so the polar key will work and fixing the webhook verification thing and then changing it so we re-use the key polar creates.
Thanks again for the help debugging!
Check tomorrow and it should accept the key!
It still crashes when I try to view the shortcuts in settings. But everything else seems better.