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.

So for sure if you can provide your source of funds and also tax returns, getting a receipt from a nearby shopping mall won't be a hard deal for you, so just get on with that and get your funds to put or play with it.