Diagnosing unknown LoRa-E5-HF module issue

If the serial ports are PB6 = TX and PB7 = RX, a serial monitor can be used.
If you use PC0 and PC1, you need to use software serial. Search for “Arduino Software Serial” and you should be able to find the information

Setting example of Grove-LoRa-E5.

edit:
File–>Examples–>SoftwareSerial–>SoftwareSerialExample