Get the IP with arping. Then trigger the gateway to retuen you a passkey for a username you can define:
# coap-client -m post -u Client_identity -k "SECURITYCODE_PRINTED_ON_DEVICE" -e "{\"9090\":\"A_USERNAME_YOU_WANT\"}" -m post "coaps://THE_GW_IP:5684/15011/9063"
Get a list of paired devices from your gateway:
# coap-client -m get -u "THE_USERNAME_YOU_HAVE_CHOSEN" -k "THE_PASSKEY_FOR_THAT_USER_YOU_GOT_FROM_THE_GW" "coaps://THE_GW_IP:5684/15001"
Get props of a device:
# coap-client -m get -u "THE_USERNAME_YOU_HAVE_CHOSEN" -k "THE_PASSKEY_FOR_THAT_USER_YOU_GOT_FROM_THE_GW" "coaps://THE_GW_IP:5684/15001/THE_DEVICE_ID"
Set devices props:
# coap-client -m put -u "THE_USERNAME_YOU_HAVE_CHOSEN" -k "THE_PASSKEY_FOR_THAT_USER_YOU_GOT_FROM_THE_GW" -f A_FILE_CONTAINING_THE PROPS_IN_JSON_STYLE" coaps://THE_GW_IP:5684/15001/THE_DEVICE_I