Review for Open Google Calendar by Jaap Dekker
Rated 5 out of 5 stars
Due to a known synchronisation problem, I switched from Provider for Googe calendar to Open Google Calendar. Works perfectly (Thunderbird 102.11), I'am very happy I can rely on a actual and synchronised calendar on both my laptop (Linux Mint 19.1) and Android smartphone.
To create your own collections, you must have a Mozilla Add-ons account.