First test the connection between your transceiver and the openSPOT2 by using the OS2's built-in local echo service on DMR ID 9999. If you hear yourself back correctly, then test the server's echo service which is usually available on DMR ID 9990. If you hear yourself back correctly, then make sure you've read
http://manuals.sharkrf.com/openspot2/en/dmr-usage-notes.html
and set up the TX contact for your transceiver's current channel to the TG ID you want to talk on.