An example operation method of an image forming apparatus includes determining a state of a toner refill operation of injecting toner from a toner reload kit (TRK) into a cartridge in the image forming apparatus, based on completion of injecting toner from the TRK into the cartridge, controlling the TRK to store information indicating a toner refill completion in a memory of the TRK, based on completion of injecting toner from the TRK into the cartridge, updating information of an amount of remaining toner of the cartridge based on an amount of the toner injected into the cartridge from the TRK, and based on the information indicating the toner refill completion being stored in the memory of the TRK, unlocking a locking apparatus in the image forming apparatus so the TRK may be removed from the cartridge.