Newbie with heltec

Hello guys, unfortunately I had to open this post because I’m having trouble getting the dev eui from a Heltec ESP32 LoRa (V2). I have experience with another ESP32 LoRa module (Pycom), but I’m having difficulties with heltec’s.

could someone help me solve this problem?
And if someone has already communicated with TheThingsNetwork and can send me a good library (there are many) I will be grateful!

Use the heltec library