Well, I'll disappoint you, pretty much NO ultracompact stroller is a stroller with a completely upright seat. I am sorry. The seatback, even of those that are relatively upright, is almost always at least a little angled, and here, it's actually more than a little angled, so no, this seat back does not sit bolt upright.
I do suggest reading this top ultracompact strollers of 2021 to inspire yourself, and, also, our Strolberry guides on how to choose a stroller... and from budget strollers (which the Chicco Trolley Me certainly is), I will only tell you - do count on MANY compromises in terms of quality, terrain capability, features of the pushchair, and, of course, the upright seat as well.
I would much rather suggest a mid-size stroller, not a travel ultra-compact one, and, also, rather a higher model - even if pre-loved - than a cheaper one (while expecting too much of it). For example, the Mamas&Papas Airo claims a rather upright seat for an ultracompact, but it's a more expensive buggy... And from Chicco, the Chicco Goody Plus is more upright than the Trolley Me BUT still not completely upright...
Perhaps look at Peg-Pérego pushchairs; they are more upright than most.