Write a SCRIPT to post a message to multiple Facebook groups

I am subscribed to several Facebook Groups.
I need to post to all the groups I am subscribed to, posting the same message simultaneously, without doing it manually, one group at a time, the procedure required by Facebook.
Facebook limits the number of times you can send the same message to different groups. Therefore, the script must be limited to simultaneously sending the message to a limited number of groups.
The script must work with a file containing a list of the Facebook group addressed, like:

https://www.facebook.com/groups/164448774036346
https://www.facebook.com/groups/427610515142804
https://www.facebook.com/groups/167837717727
https://www.facebook.com/groups/391179991014003
https://www.facebook.com/groups/711467288893817
https://www.facebook.com/groups/289245155556531

I use an Apple Mac, and I use Python for a different script with the following command:

How to Open Terminal
Change Current Directory To Desktop
>>> cd Desktop
Write Python Command
>>> python3 main.py