Getting error CS1061 in Unity - event does not contain a definition. I'm unable to fix this issue

Unity Engine
1

ERROR- Assets\Scripts\GameManager.cs(17,28): error CS1061: ‘Button.ButtonClickedEvent’ does not contain a definition for ‘AddListner’ and no accessible extension method ‘AddListner’ accepting a first argument of type ‘Button.ButtonClickedEvent’ could be found (are you missing a using directive or an assembly reference?)

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using Button = UnityEngine.UI.Button;


public class GameManager : MonoBehaviour

{
    public DroneController _DroneController;
    public Button _FlyButton;

// Start is called before the first frame update
void Start()
{
    _FlyButton.onClick.AddListner(EventOnClickFlyButton);
}

// Update is called once per frame
void Update()
{
    float speedX = Input.GetAxis("Horizontal");
    float speedZ = Input.GetAxis("Vertical");
    _DroneController.Move(speedX, speedZ);
}

void EventOnClickFlyButton()
{
    if(_DroneController.isIdle())
    {
        _DroneController.takeOff();
    }
}
2

I think you have a typo there, have you tried “AddListener”? It’s missing an “e”.