Lolz,
The op already answered you, understand that this days, almost every registered and licensed online gambling casinos have made kyc a mandatory process which every gambling user must undergo at the present time or registration or sometime in the future for some casinos, the pop up on coins.game is a primary level kyc which perhaps, does not require you submitting any documents, what they ask is just a way for them to get to know who their latest customer is, and personally, I feel theyve been and still are very generous enough to have included a free spin as in incentive or gift if you decide to comply with their policy, there are many other casinos out there where you will be required to provide all your personal details without any gift or incentives from them.

So, if you are a genuine person who has nothing to hide, I don't see a reason why you should find providing your personal information as a big problem, it's just a way for the casino to know who their latest customer is, like I said before.