Like, online? They’re in the show from the first ep, but the teacher just seems like a regular background adult at first, unless you pick up on this blink or miss it moment:
There’s so much going on and so many characters being introduced in this first ep, I don’t think we’re really meant to realize yet, only in hindsight when it’s revealed on the show.
I prefer Alex/Isabela as a ship, although they’re just friends. The teacher’s barely present, and tbh, Alex doesn’t get that much screentime either, but in the last half, most of it is with Isabela.