It's supposed to ask for Bluetooth access at that point, did it?

Also from the GitHub page:

if you don't see the scan starting, you might need to enable Foreground Service on your particular phone in the Settings menu [in the app's settings, not the phone's]

It worked for me after I looked at the settings screen. I'm not sure why. If it is working, though, the debug box will fill up with a ton of text.

Ditto

I think you need to give it a sec or hold. The button down. The same thing happened to me. But it was scanning within a min of downloading