You should enter serv230 or localhost or 127.0.0.1 or the IP address of serv230. See: https://help.qlik.com/en-nprinting/17.3/Content/DeployingQVNprinting/Installing-qlikview-nprinting.htm
"...If the is installed on the same computer as the you can use the loopback network interface, so that you can insert the IP address or . In this case it is not necessary to open firewall ports on the public network interface."
You specify the Proxy address of the Qlik Sense server and the App ID when creating the Connection to the Qlik Sense app . See: https://help.qlik.com/en-US/nprinting/17.3/Content/GettingStarted/HowCreateConnections/Create-Connections.htm
HTH - Daniel.