Avenir license on images (commercial use)

Hello, I’ve been googling about this for a while now and im still confused (even after contacting Linotype).

I draw illustrations (on Procreate app, on my iPad Pro) that are movie-like, so I add “fake” subtitles to it, and I’ve been using Avenir Heavy which already comes pre-installed on the iPad.

NOW, ive only been posting these images on social media, but what if I want to sell them as a poster or something else? I always thought that pre-installed fonts were free to use for commercial, but Procreate mentioned in their social media that they are not.

I then contacted Linotype about licenses and they said I could buy a desktop license and install it again, but since I already have a pre-installed version, that the EULA should be from Apple side and not from their side?

so… can the pre-installed Avenir Heavy be used in my images, commercially? (Using procreate and ipad)