LoRaWAN Sensor with ADF-web Gateway

I am new to LoRaWAN. I try to connect a sensor to a gateway which allows me to fetch the data via OPC UA.
But it seems I cannot connect to the sensor.
Gateway: ADF-web HD67F38-B2-868MHz
Sensor: Milesight EM300-TH-868M
second sensor which also does not work(because I have no Appkey):Talkpool OY110

Is there somebody who is familiar with this topic?

BR Martin

Are your gateway and sensors able to join the LoRa Network Server (LNS)? Which LNS are you using?