How to override referrer in Google Analytics after refresh from window.location.href

Question

Issue Steps:

1. client search on google;
2. google gives a link of mysite.com/page-a; and client clicks on the link
3. At this point, the referrer is "www.google.com", which is correct
4. There is internal logic in the website, redirect and refresh to new page mysite.com/page-b, via reset window.location.href, this needs to be kept
5. At this point, the Google referrer is '', which it thinks the traffic is from its own website. (direct source, which is wrong)

How can I programmatically change to tell Google Analytics to reset the referrer?

Through js?: gtag("set","referrer", "www.google.com")
Or script?: https://www.googletagmanager.com/gtag/js?id=MyIDXXXXXX&dr=www.google.com 

Answer 1

Well, first of all, you're supposed to be using a different field as per Google's Documentation:

gtag('set', 'page_referrer', 'https://example.com');

Secondly, you should mention whether you're using UA or GA4. I'm presuming GA4 due to gtag usage.

Finally, you can do it in GTM via setting the page_referrer field like so: