NAT describes the translation of network addresses behind and in front of the firewall, which is why the input and output IP address is specified here, as well as the port over which the connection runs.
To add a new NAT/ACL entry, either press the Create button in the grey top menu or press the Create button in the middle, if there are no entries yet.
In the editor you are able to enter an external and corresponding internal IP (you can look them up in Subnet) as well as TCP Ports and an additional comment.
