Need help with router question - pushState?

I want to be able to load a subpage from a link in the browser.
So if I navigate to lets say https://mydomain.se/shop2/?produkt_id=2439 in the browser that it will load that page. Do I have to use pushState for this to work? I guess so.

I have an actual page at https://mydomain.se/shop/shop2.asp?produkt_id=2439
And if I navigate to that address in the browser then it loads only that page of course, it is not loading it through the index page, so no css or js files are loaded.

And if I load it from my index page from a link, the link is https://mydomain.se/shop2/?produkt_id=2439

But if I just navigate in the browser to https://mydomain.se/shop2/?produkt_id=2439 then it is not found and I get an 404 error.

So my question is how can I have it set up so I can navigate in the browser to https://mydomain.se/shop2/?produkt_id=2439 and it will work, loading it with the css and js files?

I need to have the actual address to the page it loads somehow? Do I have to use pushState? And if so, what do I have to do to make it work?

In my routes.js I have this.

{
    name: 'shop2',
    path: '/shop2/',
    url: './shop/shop2.asp',
    options: {
        animate: true,
		ignoreCache:true,
        //reloadCurrent:true,
		force:true
      },
  },

I tried to set pushState:true in my view, but then it is not loading the startpage in the mainview when I load my index page?

view: {      
  pushState: true,      
},

If I understand it right I need to use pushState but I donĀ“t understand how to use it?
Any input really appreciated, thanks.