i believe you need distance. but you'll loose resolution. the lens distortion will be way less fish-eye'e if you take the picture from meters away instead of centimeters.
photo software like darktable also has lens correction for lots of camera-lenses. but not for smartphone lenses i believe. 🤔 not sure though.
The app has a "places" feature where you can set the locations where a specific alarm is allowed to go off.
So you don't really need a travel qr code.
But the app is a bit weird to configure with their profile-concept, etc. so i needed a few tries to get it right; which is why i have a small qr-code print in my wallet. ☺️
Well, jeah, i usually don't like those too much either.
But then i just open the url and read the script line for line.