Some crypto casinos ask for such documents to prove that you leave in the location you filled to leave in, most casinos that I see this kind of special receipt request more secure in terms of account security reasons is that with such documents requirements it will be hard for imposters with gamblers stolen documents like license or even government ID numbers that manage to bypass the normal documents kyc won't be able to provide such receipt a d at that there will get nailed from that point.
I would have understood this procedure if there was suspicion that someone else was using the account and not the owner or that an attempt to manipulate the system was detected. In Op's case, the situation is much less complicated and the amount he wants to withdraw is very small and hardly worth mentioning. In the end, what do we have? Op managed to complete the withdrawal despite the useless blocking. The casino wasted his time on useless tasks that prompted Op to leave the site forever and come to the public forum here to tell his experience, which may encourage many others not to try this casino.