Hello, everytime I try to compile and upload [example from this repo](https://github.com /HelTecAutomation/Heltec_ESP32) I receive this error:
/home/xxx/snap/arduino/current/Arduino/libraries/ESP32_LoRaWAN-master/src/region/RegionKR920.c:635:72: note: each undeclared identifier is reported only once for each function it appears in
/home/xxx/snap/arduino/current/Arduino/libraries/ESP32_LoRaWAN-master/src/region/RegionCN470.c: In function 'RegionCN470TxConfig':
/home/xxx/snap/arduino/current/Arduino/libraries/ESP32_LoRaWAN-master/src/region/RegionCN470.c:550:64: error: 'LORAWAN_PREAMBLE_LENGTH' undeclared (first use in this function)
Radio.SetTxConfig( MODEM_LORA, phyTxPower, 0, 0, phyDr, 1, LORAWAN_PREAMBLE_LENGTH, false, true, 0, 0, false, 3000 );
And I don’t know what to do with it. I tried defining LORAWAN_PREAMBLE_LENGHT, but I got the same issue. How can I fix it?