You can hide or delete this question if it's against the rules but I'm only asking because I need Zeraora to have a Complete Pokedex (Mythicals included) in USUM and I unfortunately missed it's event at the time. If anyone can find a way to help me or still has one in USUM, please let me know. My 3DS FC should be on my profile.
This event has ended and a couple months after the event ended back in 2018, codes would not be able to be put on the game. In other words, even if you had the code you wouldn't be able to get Zeraora.
Hope I helped!
Legally? No. Cause even if you get a code it won’t work since they expired.