It’s not a stupid question at all. Unfortunately it appears that Vectornator does not save the svg in 96dpi resolution as a Glowforge requires.
I figured out a workaround that works, based on this posting, but it’s not pretty. Basically you have to go into a code editor and change the viewbox parameter to width=“1in” height=“1in” viewBox=“0 0 72 72”. If you want a step-by-step on how to do this on an iPad, let me know. It requires a third-party code editor (I’m using Textastic).