Hi,
If the Web UI is on the same machine as the EMS, just enter 127.0.0.1 as the EMS IP address.
If the Web UI is on a different machine, you need to modify the EMS config.lua to allow remote access. In configuration > applications > rootDirectory > acceptors, under CLI aceptors, for protocol="inboundHttpJsonCli", change ip from "127.0.0.1" to "0.0.0.0" to allow remote access from any IP address. You may also set ip to a specific IP address to limit access.
Note: The EMS needs to be shutdown before modifying config.lua.
Cheers,
Don