Save display state of WKWebView

I want to be able to save the state of a WKWebView when a user quits out of my app and be able to restore it to exactly how it was when the user returns to the app. I want it to restore websites with forms, online calculators that store the history of calculations, or any websites that make Javascript objects dynamically. How can I do this?

I have tried the createWebArchiveData method here but when saving and restore a web archive version it doesn’t put the display data back exactly how it was. When I restore it from a web archive it is like I just refreshed the page which is not what I want.

I am not able to use any of the HTML5 storage methods or use any evaluateJavaScript methods to handle this since I want to be able to save and restore the state for any website I visit.