i'm trying to make a racing game on android using unity.. a have a problem if i wanna make a car move forward when i touch an image button like in the picture below.. i've already make it work but using my laptop keyboard using letter "a" and "d".. if you have any refference please let me know :)

I'm trying to make a racing game on android using unity. I want to make a car move forward when I touch an image button like in the picture below. I've already made it work using the keyboard. How do I do the same with on-screen buttons and touch input in android?