Then, the question about how someone wins a prize in the form of an item such as an iPhone has already been asked by someone under your post so I don't need to ask again.
Based on similar situation in other casinos where the prize is in a form of physical item, there are always 2 possibilities.
1st possibility is the casino allow the players to exchange the physical prize into credit or money, and the 2nd possibility is the casino do not allow it which means that the winner should give the address to receive the prize.
I have no idea about the term in coins.game about this physical prize but I guess they are friendly enough so I think the winner can ask to exchange the physical prize into money.