What is the ruling on not fulfilling an oath to donate money, which I swore upon the Qur'an to do after passing exams, knowing that I am 16 years old, and must I fulfill it?

It is recommended to fulfill an oath and disliked to break it. Therefore, if one swears to do something disliked or to abandon something recommended, it is sunnah to break the oath and disliked to fulfill it. If one swears to do something recommended or to abandon something disliked, it is disliked to break the oath and sunnah to fulfill it. If one swears to do something obligatory or to abandon something forbidden, it is forbidden to break the oath and obligatory to fulfill it. If one swears to do something forbidden or to abandon something obligatory, it is obligatory to break the oath and forbidden to fulfill it. If one swears to do something permissible, they have the choice between breaking the oath and fulfilling it, with fulfilling it being preferable, as Allah Almighty says: {and guard your oaths} [Al-Ma'idah: 89]. If you do not fulfill the oath, then you are obligated to offer the expiation for an oath mentioned in Surat Al-Ma'idah (89): feeding ten poor persons, or clothing them, or emancipating a slave. But whoever cannot find [the means] - then a fast of three days.