Is it permissible for a student to submit a forged medical certificate to justify his absence from studies, knowing that he was not ill, and that is after all his other justifications were rejected?

Falsifying a medical certificate for someone who is not ill is a false testimony, and it is among the greatest major sins, as the Prophet, peace and blessings be upon him, said: "Beware! And false speech and false testimony." It is not permissible for a student or a doctor to seek such a certificate. However, if a student is compelled to do so to save their years of study, it is permissible for them, and the sin falls upon the one who forced them into it.