I want to point my domain to a port

i want to port a domain of mine to a random port i did (6251) but when i try to go into the apps to install portzilla, the apps are gone, so does anybody have a idea on how to port?

You can use Origin Rules:

Hostname equals yourwebsite.com (or if its a subdomain, subdomain.yourwebsite.com, etc)
Override Destination port, and then you can access your site via normal ports (443), and Cloudflare will just send traffic to the port you set for that hostname.