Accept it or not, we need a domain for branding ourselves or our business. Recently I did the setup of my laravel app using these steps : Now it does not look good to share my app with a large url of application provided by cloud run.
Now back on your domain mapping page of GCP, you will have your domain verified under Select a verified domain drop down, like I got samo.cloud. Once you add your verified domain, GCP will give you a list of A and AAA DNS records to be added to your domain provider.
Add you will have successfully mapped domain for your website or web application on GCP.