After the devices factory reset, why I can't use face recognition

Question

I reinstall face app,but it can't work.

Answer 1

Because after factory reset,the activation file was deleted. Need to re-activate.
You need to contact the manufacturer to check the activation code and provide the serial number of the device.( android 9 path:setting>about tablet>hardware&model)
Please download the activation software and guide here（Tip:When you are activating, be sure to turn on the OTG button）:https://terabox.com/s/1-lKpBJFGX0KXJTDDloVXKA      or
https://mega.nz/folder/F6QXAbBS#_C80gcTE6HV5xde1r0Wupw