I'm making a 2D platformer in Unity, how to make button controls on android?

Question

2D

Created a 2D platformer, created enemies, a system of character death, killing some enemies by him.
Is it controlled through the keyboard as usual through Input W and horizontal, but the game is created for android devices and you need to control it not through the keyboard, but by pressing the buttons on the smartphone screen?
Brothers in the shop came to you with their own question, how to achieve this in the most optimized and correct way?

Answer 1

Here

Answer 2

Watch the video to solve the problem!