Is failing to erect a mourning tent for the deceased, as he had willed, and instead donating its cost to pay off his debt, considered a dereliction of duty towards the deceased?

The first thing to be disbursed from the deceased's estate, after the expenses of preparing the body for burial, is the settlement of their debts, based on the Prophet's (peace be upon him) saying: "There is no deceased person who dies owing a debt but that he is held in pawn by his debt. So, whoever frees a deceased person from his pawn, Allah will free him from his pawn on the Day of Resurrection." Erecting tents and spending money on condolences is unnecessary and impermissible to be spent from the estate unless with the permission of the heirs, especially if there are minors among them.