trx-control is not a standalone app. It requires a trx-control(7) installation with a running trxd(8) daemon that has WebSockets enabled.
The app connects to trxd(8) using a WebSockets and displays all transceivers and extensions that have been configured for client access.
The trx-control app is mainly used by radio amateurs to operate transceivers and other hamradio related hardware.
Please note that in order to use the callsign lookup feature, a valid QRZ.com subscription is needed.