Asking for leave with the teacher's signature, the law will not regulate your behavior, it should be regulated by school rules, not prohibited, generally no problem. Talk to the teacher.

If the school wants to punish you, you should discuss it with the school. If negotiation fails, you can bring a lawsuit to the court. After all, punishment has a great influence on people. (Even if the school rules and regulations expressly stipulate that this kind of situation will be punished, if the relevant administrative regulations of the state do not regulate this kind of behavior, or the punishment is light, you should sue to safeguard the legitimate rights and interests. Because the formulation of school rules cannot conflict with the law)

hope this helps