Yeah, finding them is difficult. Lots of Internet wandering. Mainly finding links through people's blogs.
I found this group recently: https://lmt2.com/
The author made a group: https://www.hackercoop.dev/
If you like fiddling with HTML, there's groups like the homebrew website club https://indieweb.org/Homebrew_Website_Club or sunday sites https://sundaysites.cafe/.
A few open-source communities have forums/channels like #showcase, where it's easy to drop a screenshot and get feedback. I'm thinking of the Discord chats for Textual and p5.js, for example, if your project uses their libraries.
Or if you're the party planning type, perhaps consider forming your own group. Even ~6 people meeting once a week for a month works well.
Everyone works on their own things.