It’s not complicated, as Keith says, you’ll need two projects, one for the data and one for the mobile app.
Take a look at this:
Setting up a mobile project with capacitor
Using dynamic data in desktop and mobile apps
You’ll need a site with ssl, and maybe you’ll fight with cors, there is a friendly advice on this topic:
Tutorial: Storing cookies/Maintaining user login on Android/Ios
Good luck and anything you need, just leave here a question 