I would recommend https://cactus.chat/ https://cactus.chat/, which is based on matrix. it has guest support (so people does not need a matrix account to commen

I would recommend https://cactus.chat/ https://cactus.chat/, which is based on matrix. it has guest support (so people does not need a matrix account to comment), but if you use your own matrix account, you are essentially joining a matrix room per post.