Please read
http://manuals.sharkrf.com/openspot2/en/setting-up-your-transceiver.html#d-star-radio-setup
(D-STAR radio setup section):
- If you want to use a reflector, set the URCALL on your radio to CQCQCQ
- If you want to use a gateway, set the URCALL on your radio to the gateway's callsign and remote module. The remote module should be the last character of the URCALL.