It asks me for the MCK code but I don't know what it is, could you send it to me again
A MCK is a mastercode that is sometimes needed along with a Network Unlock Code NUC to unlock the phone to all Network's so it accounts any Network's Sim Card.
Your Network would usually supply the MCK.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.The advice I offer is my own and does not represent Samsung’s position. I have no affiliation with Samsung.