Can we find MacBook serial number in the logic board?

Hey community!

i recently got my logic board replaced because my MacBook wasn’t turning on anymore , and the repair guy handed me my old one as well and I wanted to verify if that one is really mine, Is there a way to find out?

also there is a little Qr cube in the back of the logic board with some numbers in, what are those for?

*model 2018 with Touch Bar*