Looking for a message vault kind of thing.

I wanted to make a game in discord (custom map), so I need someone who administrates the moves (me). but at the same time I wanted to see if I could participate too.

Is there some kind of website or robot, where people can write their moves and the bot reveals them only after everyone has answered or X time has passed?

If there is another way I could be gm and play at the same time, I would greatly appreciate it. We can't play through vdiplomacy because the map has copyright.

:)