u/Dear-Championship-73

I took an "official" free USMLE Free 120 exam yesterday from the following link: https://orientation.nbme.org/launch/usmle/stpf1

but then today, apparently there is an another "official" free 120 exam which I found via Bootcamp - https://www.starttest.com/custom/usmle/?stpf1

the exams are unique but it seems that there is some small overlap in questions between the two either way

So which one is the official exam??