CubeCell HTTC-AB01 can't conect to The Thing Stack (TTN v3)

Hi guys, I’m from Brazil and this is my first post here and I would like your help. I’m a newbie when it comes to LoRa/LoRaWAN and I’m having some issues in the project I’m working on.

I built a LoRa gateway using a Raspberry pi 3 model B + Dragino LoRa GPS/hat and the code I used for the gateway was this .

So, as I am from Brazil, I connected my gateway to The Thing Stack using the frequency plan AU_915_928_FSB_2.

So, the gateway is apparently working and sometimes receives some uplinks from some devices nearby. But when I try to send a package from my node to my application on The Thing Stack, it doesn’t work.

The node I’m using is a Heltec CubeCell-Board HTCC-AB01 and this is the code I’m using:

I actually was receiving some package from my node, but it was in a random way and after that I couldn’t receive it anymore.

But now, whenever I try this is what I see on the Arduino IDE serial console and nothing else happens

Here is the link where the information is more accurate with images and code as well.