With a piaware sdcard image:
piaware-config receiver-type relay
piaware-config receiver-host (whatever)
piaware-config receiver-port (whatever)
It expect Beast binary format data on the given host/port and will relay it locally to skyview / piaware / mlat-client.
With package-based piaware installs, use receiver-type other (the ‘relay’ bits are only present on sdcard images)