Rated 4 out of 5 stars

Excellent and very easy to use add-on. But latest version 3.2.0 is not compatible with Firefox 78.11.0.

Hope and wish it gets evolved, for now I'm temporarily using with success alternative add-on Google-4-TbSync:
https://addons.thunderbird.net/en-US/thunderbird/addon/google-4-tbsync/

This user has 2 previous reviews of this add-on.