Redirect Subdomain On One Domain To Same Subdomain On Another Domain

How do I redirect to without using a page rule or a worker?

“abc” should be whatever the user requests. Not just “abc”.

Do the redirect on your origin?

Page rules are by far the easiest way to do it. Any reason why you don’t want to?

Cloudflare is my origin.

Yes. They’ll reach EOL. I want to stop using them.

Use the redirect rules, needs some string slicing…

When page rules are gone, will they:

  1. Migrate to something else, like redirect rules?
  2. Have a way to be recreated in something like redirect rules without using custom typed out expressions (and the ability to use asterisk?)

How do I need to modify that to get it working how I want it to?