What is the ruling on being absent from work with the direct supervisor's knowledge, while receiving a salary, given that the institution is shut down, the residence is far, and transportation costs are exorbitant, and is the money earned considered unlawful gain?

If the direct supervisor, who is authorized by the employers, permits an employee to be absent for a benefit he perceives, then there is no harm in that. However, if he is not authorized, then the employee is obligated to attend according to the signed contract, because Muslims are bound by their conditions. In the event of absence without permission, the money received for the period of absence is unlawful and must be returned to the employer.