In Spider-Man: Far From Home Mysterio thanks a scientist for giving him a believable back story, what is this guy's name?
Beck mentions his name during the speech:
Quentin Beck: To Guterman; the story you created of a soldier from another Earth named Quentin fighting space monsters in Europe is totally ridiculous, and apparently exactly the kind of thing people believe right now!
Spider-Man: Far From Home
And whilst I'm pretty sure your title is written as it is to avoid spoilers I think it's worth being explicit here: There are no other Earths in Far From Home, it was all made up.