Permission denied for REST server launching

Question

Hi,

I have a REST server, written in Java, that I was trying to run inside an Azure Virtual Machine. My application gets an IP and a port as arguments to run the server.
By using the virtual machine public IP address and a specific port that I created a rule (tried inbound rule, outbound and both), the server does not start because I have not permissions to bind the server on the inserted arguments.

What should I try to do?

Note: I use a student subscription.