Hello Andy,
Good day. Thank you for the query.
Please advise if you are referring to the way to enable the Blue Puck RHT, if yes then you will need to have a phone or device with NFC function. Firstly, you will need to download the Device Manager Mobile application on your phone - https://play.google.com/store/apps/details?id=com.ela.mobileapp.elamobileapp&hl=en&gl=US
Next, you will need to start the application, Device Manager Mobile > Configuration > Enable > Scan the sensor close to the phone. Likewise for disabling, Device Manager Mobile > Configuration > Disable > Scan the sensor close to the phone. I have attached some images below for your perusal.
You may follow the same steps for disabling the sensor. Also, you may refer to https://teltonika-gps.com/downloads/en/blue-puck-t/Sensor-and-Beacon-testing-instructions-v1.2.pdf on how to configure the sensors.
Please go through this and let me know if it helps.
Kind regards.