Is it permissible for a female student to submit a forged medical certificate for one of her parents in order to be absent from a subject's exam, and then obtain a grade in it later? And would the appointment or job resulting from this grade be unlawful (haram)?

Presenting a forged medical certificate is a clear sin, and it falls under the forbidden categories of false speech and deception, based on the words of Allah Almighty: "And shun false statements" (Quran 22:30), and the words of the Messenger of Allah, peace and blessings be upon him: "Shall I not inform you of the greatest of major sins?" We said, "Yes, O Messenger of Allah." He said, "Associating partners with Allah, and disrespecting parents." He was reclining, then he sat up and said, "And indeed, false speech, and false witness." And due to his saying, peace and blessings be upon him: "Whoever deceives us is not of us." What is stated in the "Kuwaiti Fiqh Encyclopedia" is that forgery is every statement or action intended to beautify falsehood, whether it is in speech, like false witness, or in action, like imitating handwriting or currency with the intention of establishing falsehood. The existence of circumstances that prompt the submission of a forged certificate does not permit it and does not remove the sin.