KeyCode to Ui ? for mobile

i'm stuck on this script the whol script use keyboard "H" and i don't how exactly to convert it to Ui touch for android

 using UnityEngine;
 using System.Collections;
 
 public class PoliceLights : MonoBehaviour {
 
 
 
     public Light[] RedLights;
     public Light[] BlueLights;
 
     public float time = 20;
 
     private float timer=0.0f;
     private int lightNum = 0;
 
     enum LightsMode {Active=1 , Inactive=2}
     private LightsMode lightsMode = LightsMode.Inactive;
 
     void Update () {
 
 
 
 
         if (Input.GetKeyDown(KeyCode.H) && lightsMode == LightsMode.Inactive)
         {
             lightsMode = LightsMode.Active;
 
         }
         else if (Input.GetKeyDown(KeyCode.H) && lightsMode == LightsMode.Active)
         {
             lightsMode = LightsMode.Inactive;
         }
 
 
 
 
 
         if (lightsMode == LightsMode.Active)
         {
             timer = Mathf.MoveTowards(timer, 0.0f, Time.deltaTime * time);
 
 
 
             GetComponent<AudioSource>().enabled = true;
 
             if (timer == 0)
             {
                 lightNum++;
                 if (lightNum > 12) { lightNum = 1; }
                 timer = 1.0f;
             }
 
 
 
 
 
             if (lightNum == 1 || lightNum == 3)
             {
 
                 foreach (Light RedLight in RedLights)
                 {
                     RedLight.enabled = true;
                 }
 
                 foreach (Light BlueLight in BlueLights)
                 {
                     BlueLight.enabled = false;
                 }
             }
 
             if (lightNum == 5 || lightNum == 7)
             {
 
                 foreach (Light BlueLight in BlueLights)
                 {
                     BlueLight.enabled = true;
                 }
 
                 foreach (Light RedLight in RedLights)
                 {
                     RedLight.enabled = false;
                 }
             }
 
 
             if (lightNum == 2 || lightNum == 4 || lightNum == 6 || lightNum == 8)
             {
 
                 foreach (Light BlueLight in BlueLights)
                 {
                     BlueLight.enabled = false;
                 }
 
                 foreach (Light RedLight in RedLights)
                 {
                     RedLight.enabled = false;
                 }
             }
 
         }
         else
         {
             GetComponent<AudioSource>().enabled = false;
 
             foreach (Light BlueLight in BlueLights)
             {
                 BlueLight.enabled = false;
             }
 
             foreach (Light RedLight in RedLights)
             {
                 RedLight.enabled = false;
             }
 
 
         }
 
 
 
     }
 
 
 
 }

i try this solution but didn't work for me

 using UnityEngine;
 using UnityEngine.UI;
 
 [RequireComponent(typeof(Button))]
 public class KeyButton : MonoBehaviour {
 
     public KeyCode key;
 
     public Button MyButton {get; private set;}
 
     void Awake() {
         MyButton = GetComponent<Button>();
     }
 
     // Update is called once per frame
     void Update () {
         if (Input.GetKeyDown(key)) {
             MyButton.onClick.Invoke();
         }
     }
 }

i use unity 5.3

any idea ?