ui button as a button on the keyboard. What to do?

Question

2D

unity. csharp. Wrote a simple script under the clave:

using System.Collections;
using UnityEngine;
using UnityEngine.SceneManagement;

public class Door : MonoBehaviour {


  public KeyCode aktion = KeyCode.E;
  public int level;
  public bool InTrigger = true;
  public GameObject door;

  public void Start ()
  {
  }

  public void Update ()
  {
    
  }
  public void pressA ()
  {
    Input.GetKey (aktion);
    print ("eee");
  }

     void OnTriggerEnter2D(Collider2D other)
  {
    if (other.gameObject.tag == "Player") {
      InTrigger = true;
    }
  }

  void OnTriggerExit2D(Collider2D other)
  {
    if (other.gameObject.tag == "Player") {
      InTrigger = !InTrigger;
    }
  }

  public void FixedUpdate ()
  {
    if (Input.GetKey (aktion) && InTrigger)  // действие, если на триггере и нажата клавиша
    {
      SceneManager.LoadScene (level); // переход
    }
  }
}

Works as it should. But how to hang an action (KeyCode.E) on a UI Button (for android)?
I'm still green in this matter, so I ask for help.

Answer 1

UI Button has Events. It is possible through the inspector, it is possible with code ( https://docs.unity3d.com/ScriptReference/UI.Button...

Answer 2

I'm a little surprised how people can not find / skip) this important tutorial)
https://unity3d.com/en/learn/tutorials/topics/user...
and the code option is excellent as GavriKos tells you.
code in practice is sometimes even better if you do not have a simple menu that is easy to remember anyway.
it will be easier to find links and where is it called and from where)