Gadgetbridge - Amazfit Auth Key

I have been unable to understand how to get my authorisation key.

I came across this site, with their apk. Is this downloadable file - Zepp 6.1.4 mod safe?

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

It runs and saves code onto phone, not on band as it says in instructions.

When I add the code with the prefix 0x it says it is trying to add, but I just get the circle going around and around.

When I go into settings it says watch is connected to phone. Any ideas?

Flakey software. Miss my Apple Watch.

For first watch I now have this screen but no connection, second watch just has as the first picture.