Port Mapping issue

[ZAHIDSHABIR08]

Hi,
As we have mentioned port no. inside the code as 8080, now if we want to do the port mapping to expose the application publicly which port number should I use for port mapping 8080 or 5000

The second thing is when we hit this URL inside (Not publicly) we are using port 5000 why 5000? because we did not mention 5000 anywhere in the code we have used port 8080 inside the code.