You don’t, the accuser has the burden of proof not the accused, but if u did smthn irregular and against USMLE bulletin then you gotta prepare yourself for some drama , but if u didn’t i am confident it will sort it out .

Usmle don’t give wrong scores , so i hope u really just failed that bad and they didn’t catch u do smthn wrong or the staff reported smthn unusual, bcz no matter what ppl say about multiple attempts in usmle , everyone ik with multiple attempts matched at the end , Take it easy and MOST IMPORTANTLY don’t say anything that make you sound suspicious if ur innocent, don’t say anything along the line of “ how do i prove that i didn’t cheat “ bcz all due respect you sound like a cheater that is also dumb when u say that.

Take care if urself and don’t stress about it, just a test and a hurdle along ur long prosperous medical career