I believe he's talking about having a player that is pay-to-play, but hasn't paid for this session. He'd like that person to still be a member of the game, but prevent him from being a part of the current session. There isn't a good way fo doing that in Roll20. The best you could do is split the party and drag that player's avatar to a page by themselves. You can even add a message about paying for the session and such. =D They'd still have the chat, and would be on the built in audio/video. Other than that, you'd have to kick them from the game, and send them a new invite after the current session. That won't block them, but they will need to rejoin. Once they have rejoined, everything will still be set up with permissions for them as it was before.