The usual rule is you have to be over 18, because under that age you aren't legally adult and can't make a contract to book a room. But the real way to find out is ASK them! They have a phone and an email address.
Hotels do not allow minors. You have to be 18 or with an adult.
Most places require at least the person getting the room to be 18.
Pick up the phone and call the hotel. Are you completely incapable of doing anything for yourself?
Pay them and they don't care. Just like you buy things in shops
This is just a thought, I have contemplated your question for six days, CALL the damn place and ask... them!