Full screen app + tell it to shrink (afaik only available if it doesn't natively declare support for the notch).
And it achieves it by scaling the whole screen ever so slightly, ruining pixel offsets everywhere and making everything fuzzy, seemingly so it doesn't ever present a non-standard display ratio despite the notch being very non-standard already, and despite full screen apps already working on external monitors that can have any ratio.
It's not an option anywhere else. Nor would I want that fuzzy mess anyway. It's such an insane design.