Rated 1 out of 5 stars

No point in listing an extension as compatible if it no longer works, surely?

This review is for a previous version of the add-on (1.4.0). 

That's way the listing says "Works with Thunderbird 68.0 - 73.0". Plus, the large warning in the description.

I'm working on getting this to work on TB78+, but I have to wait for some changes on the Thunderbird side.