As far as I have seen on the internet forums , Feather RFM9x LoRa module is not having a LoRaWAN stack on it. But few say a LoRaWAN stack can be implemented on it using a LMIC library. Please can you check the following link and tell me the possibility
https://www.thethingsnetwork.org/forum/t/adafruit-lora-feather-gateway/2440