Why is the tablet not charging after I plug in the USB cable

A: Please note that the tablet cannot be charged by USB cable, please use the original DC power adapter to charge or you can buy a charging dock in our store, the link is as follows:

Power adapter parameters:

AC100V ~ 240V、50Hz/60Hz output DC 5V/3A ；

USA standard ： CE approved；

Plug:7cm（W）*4.2cm（L）*6.8（H）,length of cable:1.2m;

weight:146g

https://www.amazon.com/dp/B0B77F2GLF?ref=myi_title_dp

Charging Cradle for Rugged Tablet