I keep getting a door lock error on this unit

That part number is for the door latch assembly, and you’re right in bringing to my attention that it’s not currently listed in our parts as available. I’ll see if I can work to get it added. In the meantime, we occasionally have to order from other vendors/websites when all else fails or explain to the customer they may need to go through factory service or can contact Samsung directly to see if they’d be willing to send the part to you.