Reverse Proxy setup using SAP PI

Hello folks,

I am trying to set up a reverse proxy between SAP Cloud for Customer and SAP PI (Java stack). And I am following the steps mentioned here:

Configuring Host Mapping, Path Prefix, and Path Mapping - Administration - SAP Library

However even after following the procedure and mapping the internal and external urls, I am not able to access the internal url through the external url.

Are there any more steps or prerequisites that I have to perform apart from the steps given in the page mentioned above.

Thanks

Ravi