Hi Mozzi.
If you have a full working PWA that meets all requirements, deploy it to the web and head over to PWABuilder. It’s a handy (and free) tool that creates the required sources for you to build a native app around your PWA. I used for a couple of smaller projects, and had no problems with app submissions to Apple.
Please also have a read here, that’s the second part of the series.
You still need a Apple and / or Google Play Account in order to release an app to the stores! You also need a Mac to build for iOS.
/heiko