(REI Clubs/Groups) How to Write to them?/How to make a group?

(REI Clubs/Groups) How to Write to them?/How to make a group?

I joined some REI clubs/Groups on here and I been looking around on how to leave messages for everyone in the group but don't know how. Is there a way to leave a message behind for the whole group? and How do you make your own Group so that investors can look into it?

Thanks In Advance

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