Explanation

Box 1: Public
The following example shows site traffic coming from both ports 8080 and 8081 and being directed to the same backend pools.

Box 2: Application Gateway
You can create an application gateway with URL path-based redirection using Azure PowerShell.
Box 3: Path-based redirection and Websockets
References:
https://docs.microsoft.com/bs-latn-ba/azure//application-gateway/tutorial-url-redirect-powershell