Your screenshot shows that you the openSPOT is successfully connected to REF030C. If you want to do an echo test, you have to connect to REF030E. Post a screenshot of the call log on the Status page which shows your call to REF030E.
The openSPOT's modem is set to the correct mode and is on frequency 433.900MHz. Make sure your transceiver is set to that frequency. You should hear calls coming from the network.
The screenshot shows that your openSPOT2 is running firmware v51 which is a very old firmware and you should immediately upgrade to the latest stable firmware v63 (
https://www.sharkrf.com/products/openspot2/changelog/
)