Allow one user to edit dns records of another

I want to create an app that allows one CF user to delegate a subdomain to another CF user.
What is the best approach to allow one CF user edit DNS records of another (restricted to a chosen subdomain)?

I tried to create a hello world app with a worker inside but it fails to get uploaded for a preview with an error: Apps with Workers is in a closed beta. I guess I need a worker to let one user modify dns records of another user (restricted to a specific subdomain). I’ve already got access to CF workers but guess it’s not the same as workers in apps – could, please, someone tell me if I need workers for my task at all and if yes then how can I get enrolled in the queue. Thanks.