Only works on Serial Monitor

So I am creating an Rc Bluetooth Car using L293D and Hc05

But the commands stop, forward, backward, left and right only work when I am testing using the Arduino Serial monitor?The Bluetooth also connects to my phone but when I press the buttons it does not do anything at all

(This is for my school project and I have been stressing and trying to figure out a solution. I only have 4 days left)