Instructions to obtain the serial number on AOSD devices

How to find the serial number on AOSD devices for free. Instructions to show the serial number on a AOSD smartphone, tablet or smartwatch to sell it, report its theft, find out if it is original or use the guarantee. Search for your device among the wide catalog of 3 available devices.

AOSD Q33 AOSD Q33
AOSD S8 plus AOSD S8 plus
AOSD Q55 AOSD Q55