Build me a social media messaging app

I want an app like this.


An app in which users interact publicly in a random group chat of their choice. With maximum of 20 users each group chat, these group chats must be according to
1. Places
2. Interest
3. Hobby
Etc. (Note that this Group chats are pre made by admin only) meaning no one can create a group chat except for admins.


Now if a user wants to do these following

1. Chat privately with other users
2. Video/audio call
3. Create their own group chat
4. Add or follow specific user.

Then they must avail the premium version of the app.


Admin panel main function:
1. Create Group chats
2. Deactivate uses
3. Receive tickets from users


Website/app must have anti flooding features if users flood messages in a group chat.