I want to move new functionality of a Web App to Azure via Hybrid Connection. If the functionality is part of the older Web App I'd like to redirect the request for older version using same URL to On-premise.
What are the ways we can redirect from azure to On-premise load balancer and wise versa considering URL not going to change?
Example : https://xyz.app.com/default
I'm not sure if this is possible since you don't want to use an FQDN with Hybrid connections. You simply want to use a domain name so that it resolves with your DNS on the other end of the hybrid connection instead of trying to do a DNS lookup against the DNS server on the app side. If on premises https://xyz resolves correctly this would work.
When your app makes a DNS request that matches a configured Hybrid Connection endpoint, the outbound TCP traffic will be redirected through the Hybrid Connection.
Note
This means that you should try to always use a DNS name for your Hybrid Connection. Some client software does not do a DNS lookup if the endpoint uses an IP address instead.
https://learn.microsoft.com/en-us/azure/app-service/app-service-hybrid-connections