Teclast x98 air 3g need help installing windows

hey! i just got teclast x98 air 3g from my university and apparently its was only on android only and it bios was locked. so i flashed the latest bios to unlock dual boot option and i succeeded. Now it has dual boot option but only shows android. can any body please guide me thoroughly on how to install windows 10 in it also with android still being available as dual option. its c8j7 model of x98 3g air.

please help i really want to use windows 10 on this with android. Any help will be highly appreciated.

Thanxx