You’re confusing LoRa with LoRaWAN - the most excellent explanation of LoRa is to be found here. Go read it & watch the short video, we’ll wait. For homework, I require you to watch this 30 minutes video which explains why LoRa is so cool; there will be a quiz later, so pay attention!
So, to recap what you just watched, LoRa is a spread-spectrum protocol patented by Semtech to transmit low bitrate data with minimal power over huge distances. You need a SX12xx chip on both ends of this distance and a microcontroller to move data around. That’s it to use LoRa - plug and play.
ON THE OTHER HAND, LoRaWAN is a Wide Area Network stack that goes over LoRa that allows secure communication and Over The Air Authentication. In addition to SX12xx chips, any sort of security requires use of KEYS.
Quick sanity check:
Q1: does the sensor come with a 64-bit DevEUI and a longer AppKey (in the form of a QR code or a sticker, say)? If so, could be LoRaWAN; go to #Q2. If not, something else and you’re on the wrong forum.
Q2: do you need to register sensor’s DevEUI and AppKey BEFORE reading any values anywhere? If yes, it’s most likely LoRaWAN. If not, you’re on the wrong forum.
You need to obtain a matching SX12xx chip & mate it to a LCD or serial port to see your data - read the part after “Next, it will show you 3 LoRa receivers to receive the senor measurement” more carefully.