Ionic 3 pass QueryString to index.html

I have an external website (and other locations) that link to my Ionic 3 PWA app… I need to pass a parameter to the PWA app. BUT… how is it supposed to be done?

the URL is basically something like this: https://pwa.mydomain.com/index.html?referrer=website

I can get the referrer using let params = new URLSearchParams( window.location.search.substring(1));

HOWEVER, using that URL changes path shown in my browser to http://localhost:8100/?referrer=website#/tabs/home/home, and subsequently clicking on anything in the app keeps the "?referrer=website in the URL shown in the browser.

I’m sure there are better ways to do this, but I’d be happy with what I have if I can just get the URL shown in the browser back to what it should be (without the QueryString).

Any ideas?

Thanks.