I run a discussion group that meets once a month - our tech stack is
1. A blog running WordPress that I use to announce meetings
2. A meetup.com account (free tier) that has the same information as the blog
3. A MailChimp account (free tier) where I send notices about the meetups
4. A very active Slack group (free tier) where I announce meetups and we have entended discussions. Discord would probably work just as well.
I've never used Facebook for anything, but the above four tools work very well for us.
I've never used Facebook for anything, but the above four tools work very well for us.