How to view subdomain traffic in GA4

By default, the data in your GA4 reports includes only the request URI and not the domain name. This makes it impossible to view subdomain traffic.

The request URI is that part of the URL that comes after the domain name.

For example, if your URL is: https://www.optimizesmart.com/contact/

Then request URI would be: /contact/

The hostname would be: https://www.optimizesmart.com

Unlike in Universal Analytics, in GA4, you don't need to append the hostname to the request URI to see the full URLs in the reports.