How can i use a port other than the ones listed?

Website, Application, Performance
1

So Im trying to add a port that is not listed on Cloudflare but the only insyructions I see is to grey out the proxy on a subdomain. I dont have a subdomain I only have a main domain. Does any one knwo how to add ports other than the ones specified?

Thank you in advance.

2

By subdomain, it means www, app, etc.
You can use an origin rule to forward the requests to different ports