Need provider for Version 78 or return to Ver 68

I use Google Calendar on my Android cell phone and was blessed that I could use Lightning for all my calendaring and have only necessary - must do items sync to Google for alerts on my cell phone. provider made it happen, but is no longer available in Ver 78. Having a separate Google calendar in thunderbird does not help unless it will sync with the new built in T-bird Calendar. How do I do that. Otherwise I need to go back to Version 68. How do I do that once I have upgraded to 78? Thanks. I really need just one calendar and I don't need google knowing everything that I want to keep personal on my Lightning calendar.