Maybe this is against the grain, but I think it's better to ask in-person. Mainly to avoid getting ghosted (usually accidental ghosting).
I'd imagine that it's really easy for professors to lose track of emails, especially when they're receiving emails from undergrads, grad students, admin, and then other people requesting LORs. I requested all of mine in person, and just sent follow-up emails with my personal statement and resume.
But, I'm sure email usually works fine!