Is it permissible for an employee who stole money from his company to return the stolen amount by purchasing supplies for the company with that money without presenting invoices, in order to avoid harm from the company's owner?

What was mentioned is sufficient for returning stolen money, as long as the items are essential for the company. By doing so, he has reimbursed the company for the cost of the stolen items, fulfilling its right. He is not required to inform the company owner or return the money in a specific manner. It is stated in the fatwas of the Permanent Committee for Issuing Fatwas: "You are required to return rights to their owners as much as possible, in a way that enables you, without them knowing it is from you, if you fear the consequences of that." It also states therein: "If the matter is — as mentioned — that the man has repented by abandoning the sin, regretting what occurred from him, and resolving not to return to it, then he must return the rights to their owners. Whoever he knows among them, he should return his right to him, even indirectly, in a way that he can, without the owner feeling that it is a gift or similar."