If the casino also accepts fiat then it would be easy and I've done it multiple times with success. However, to recommend a crypto-only casino, your friend needs to be familiar with crypto and it adds more work to explain things to them. I've done it but, well, I'd just say join this casino (the one with fiat deposits) after I tired of explaining "You need to go to the exchange, do KYC, and this and that."
It seems to me that any recommendations (especially when it concerns money in any respect) are not very good. Or if you still want to recommend, then try to do it without mentioning the name of the casino, let him try to find one that suits him, or if he asks where you play, then you can say. I do not like to recommend because if any problems arise later, you can be blamed for this. But I am sure that now every player knows about online casinos.
It can be done with a disclaimer like this casino is reputable on the forum.
You can try this instead of playing on some shady offshore casino with no license. For sure your win/lose isn't my problem lol.