No data seen in the TTN from the RFM96

Hello. Newbie here. I’m trying out to build a LoRaWAN network. I used a RFM96 transceiver module by Adafruit as my end node and used RAK2287 Concentrator Module as my gateway. I already connected the RAK2287 to the TTN and registered as well my end-node. However, I didn’t see the data it sends. I followed everything in this video LoRa/LoRaWAN Tutorial which is part of the series made by a youtuber named Mobilefisher for LoRa/LoRaWAN.

Once I opened the serial monitor of my Arduino IDE, I always get this:

I also modified the code and put the specification of my registered end-node in the TTN but still to no avail.

I hope someone can shed light about this. Any insights would be deeply appreciated. Thanks!