Flysky GT3B can't reverse?
 

Hi guys,
I recently bought a flysky gt3b like 3days back and have installed the transmitter into my RC car (TT01d), but for some reason, it can only move forward and not backwards(reverse).
I have tried resetting the ESC but it didn't work.
My TT01D specifications are below.
Can someone help me out?

TT01D:
TEU101BK ESC
Tamiya Sports Tuned Motor
Sanwa Servo
Flysky transmitter
Flysky GT3B remote