I did my first startup while experimenting with QGIS. I accidentally pasted wrong identification key and wasn't able to get anything other than Python errors. I contacted support and got a fast answer that it's a bug but there's a workaround. You just needed to delete the false key written in QGIS3.ini which you can find in Settings-User profiles-Open active profile folder, and after that the plug-in asked for the ID key once again and as expected it started working just fine with a correct ID key.