The number needed for data transfer over your cellular connection
isn't on the unit.

Ricardo Vassmer <<rvassmer>> writes:

For the Flymaster tracker it is necessary to contact them
directly.

https://www.flymaster-avionics.com/page/tracker

Number is not in the box, manual or anywhere in the device. Also on Airtribune
it is necessary to put the complete 6 digit serial number. If you only put the
last 5 it won’t work.