Lock roster on Sleeper?

Hey everyone,

So I am having trouble collecting league dues from some of my league mates. It was my fault, I waited this long to ensure we were mostly in the clear with covid, but I digress.

Do you know how to lock a roster on Sleeper? I don’t want them to be able to make any roster moves or waiver claims so I can force their hand. If you can’t do that, do you have any other ideas?

I would send like a group message and there a couple people who haven’t paid and so you all aware if you win the league and you haven’t paid you are not winning the money at the end and it will go to 2nd unless they didn’t pay etc etc