Minors need their parents to sign anything, because only they can guess your legal guardian, before you are a minor. It must be under their protection. Even if you make a big mistake, the police require your parents to be present. Otherwise, it is illegal.

You don't have to have an ID card to go to the hospital, but you should also ask your age unless you lie. Otherwise, this is impossible. Although I don't want your ID card, the doctor still needs your parents' signature according to your age during the operation. You'd better not go by yourself, because circumcision is also risky. Once the problem is solved, you will regret it all your life.