my action button wont play in my cell phone android

I need to add the code to allow the action button to work in playing the game in android cellphone the action button doesn't play rite now because I don't have the mobile android coding added

Please heklp me add the mobile coding to the script so the button "g" will work in the cellphone android

my action button is set to "g" in the pc but when I try to play the game on the phone it wont move what mobile code do I need to add to make this action button works in playing the game in the phone?

how do I add or alter the buttons so they work in the game I see when I changed the unity editor preference to device selected " any android device" the button wont even work on the pc

so whats the universal setting or code I add to make the buttons work on both pc and mobile? please somebody help

it worked fine on the pc in unity

its a android cellphone

 using UnityEngine;
     using System.Collections;
 
     public class hok : MonoBehaviour 
     {
         public float upForce;            //upward force of the "flap"
         public float downForce;
         public float forwardSpeed;        //forward movement speed
         public bool isDead = false;        //has the player collided with a wall?
 
         Animator anim;                    //reference to the animator component
         bool flap = false;                //has the player triggered a "flap"?
 
         void Start()
         {
             
             anim = GetComponent<Animator> ();
             
             GetComponent<Rigidbody2D>().velocity = new Vector2 (forwardSpeed, 0);
         }
 
         void Update()
         {
             
             if (isDead)
                 return;
             
             if (Input.GetKeyDown("g"))
                 flap = true;
         }
 
         void FixedUpdate()
         {
             if (flap)
             {
                 flap = false;
                 anim.SetTrigger ("Flap");
                 GetComponent<Rigidbody2D> ().velocity = new Vector2 (GetComponent<Rigidbody2D> ().velocity.x, 0);
                 GetComponent<Rigidbody2D> ().AddForce (new Vector2 (0, upForce));
             }
 
             if (Input.GetKeyDown("t"))
             {
                 
                 GetComponent<Rigidbody2D>().velocity = new Vector2(GetComponent<Rigidbody2D>().velocity.x, 0);
                 GetComponent<Rigidbody2D> ().AddForce (new Vector2 (-0, downForce));
             }
         }
 
             
     int hit = 0; 
 void OnCollisionEnter2D(Collision2D other)
 {
           if(other.gameObject.tag == "Wall")
     {
         hit++;
         if(hit >= 25)
             Destroy(gameObject);
                }
     if(other.gameObject.tag == "Wall")
     {
     }
 
 }
 }