Am I obligated to pay the commission for the website that sold my car, even though I swore to pay it, and I am unable to do so due to my debts?

The agreed-upon commission with the website must be paid. Failing to fulfill this obligation places the doer in the sin of breaking an oath, neglecting a right, and unlawfully consuming people's wealth. This is based on the Prophet Muhammad's (peace be upon him) saying: "Indeed, the gravest sins in the sight of Allah are: a man who marries a woman, and when he has fulfilled his need from her, he divorces her and takes her dowry; and a man who employs another man, then withholds his wages." And his saying: "Give the laborer his wages before his sweat dries." And his saying: "There is no faith for one who has no trust, and no religion for one who has no covenant." The fact that the questioner is in debt or poor does not justify neglecting rights. The commission is a debt that remains binding until he is able to pay it, in accordance with Allah's saying: "And if there is any debtor in difficulty, then grant him time till it is easy for him to repay."