2018 SR5 Premium key fob programming

Okay so idk if I’m going crazy or my memory is shot, but I’m trying to program a new key fob, I’ve done it before, and I cannot get into programming mode. Am I forgetting something? Can you not? Is it the cycle locks 5x or the open doors method? Long story short my gf lost my key so to be safe I got a couple off Amazon, had 1 of them cut and then had to have some guy program the actual key to start the car, but then I went into programming mode and set the key fob to lock/unlock doors by entering programming mode and holding down lock/unlock. The buttons on that key broke so rather than cut another key I just swapped the button mechanism with another key, but I cannot get into programming mode to add this key fob. Am I missing something? Can you not manually program JUST the lock/unlock, not program a master? I swear you just do the lock/unlock cycle to enter programming mode and I’m just messing up, but it’s driving me bananas. You literally cannot find any information/videos on how to enter programming in a 5th gen.