What is the ruling on assisting in the creation of a website to enable piano teachers to organize their students' appointments, which includes a payment feature after booking?

If the aforementioned website is dedicated to teaching music and assisting with it, then it is not permissible to create it, due to the endorsement of evil and assistance in it that it entails. Allah (the Most High) says: "And do not cooperate in sin and aggression." Indeed, the one who assists in sin is a partner in it, and the one who points to evil is like its perpetrator. Assisting in disobedience to Allah is forbidden, and the helper bears a burden like that of the one who commits the sin.