I have a 2012 850 xp. Today while riding I noticed something dripping under the atv. I check it out and see it is coolant coming out of the radiator cap. The overflow seem just about empty. I check radiator and it looks empty. All I had with me was water So I put some in to make it home. The bike never seemed to get hot. No error lights. but it kept leaking through the radiator cap itself. It did get low on coolant and start blowing bubbles in to the overflow tank.
So it is now parked. Riding it was fine. No bad noises no difference in anything. Besides the coolant coming out of the cap.
From reading here it seems to be it is either a bad radiator cap or bad head gasket. I don’t see fluid leaking from anywhere else on the bike.

Can someone please help me here on what it could be? If I get the cap tested and it is bad, does that mean it is likely not also the head gasket? And what type of coolant should I buy to refill?