This is not going to be easy.
So “Python” was nowhere in that last paragraph, which means there isn’t (AFAIK) a cross-platform way to write Python in mobile apps. PhoneGap turned into Cordova, which now in Ionic-land is being subsumed by Capacitor. So the first thing I would ask myself if I were you is:
Do I absolutely, positively, need this to be in Python, or can I rewrite it in TypeScript?
If there’s a chance to reimplement it in TypeScript, I would absolutely go that route, because it will be futureproof and much more lightweight to deploy and work with.
If there isn’t, you’re going to need to try to figure out how to embed a Python runtime environment and interact with it via Capacitor. Cursory Googling came across this project for Android; I have no clue whether anything remotely similar exists for iOS.