How do I get rid of the default Pages domain altogether when using a custom domain?

I have a cloudflare Pages application running, and as such it is accessible using project-name.pages.dev, but I also have it setup to use a custom domain
example.com
(the custom domain is managed by cloudflare dns). How do I prevent the project-name.pages.dev domain from being active, there fore only allowing access from
example.com
?
Was this page helpful?