Is it permissible to resign from the current job, in which one does not actually report for duty, knowing that there are car installments under a Murabaha contract that end after one year, and is it necessary to wait until the car's value is paid off?

The salary of a public sector employee is permissible if their employment aligns with regulations and they commit to performing the duties assigned to them by the system. As for car installments, they have no bearing on the permissibility or impermissibility of the salary.