Currently, the example code for LoRaWAN protocol is based on STM32L151CBU6 (indeed the LoRa Node 151 is STM32L151CCU6), the debug log output via UART1, it means if output the logs, users need a USB-UART bridge.
In order to meet the low power characteristic, we closed the log output default via macro definition.
Define USE_DEBUGGER or add it in Keil options to enable it:
If everything is ok, it should be such an effect: