XRBaseInteractable does not contain a definition for OnSelectEntering - unity3d

Question

I am tring to follow this tutorial https://www.youtube.com/watch?v=gmaAK_BXC4c to make a vr gun but I am getting an the following error:
'XRBaseInteractable' does not contain a definition for 'onSelectEntering' and no accessible extension method 'onSelectEntering' accepting a first argument of type 'XRBaseInteractable' could be found (are you missing a using directive or an assembly reference?) [Assembly-CSharp]csharp(CS1061)
for the following lines :
socketInteractor.onSelectEntering.AddListener(AddMagazine);
socketInteractor.onSelectExiting.AddListener(RemoveMagazine);
Here is my code :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.XR.Interaction.Toolkit;
[AddComponentMenu("Nokobot/Modern Guns/Simple Shoot")]
public class SimpleShoot : MonoBehaviour
{
[Header("Prefab Refrences")]
public GameObject bulletPrefab;
public GameObject casingPrefab;
public GameObject muzzleFlashPrefab;
[Header("Location Refrences")]
[SerializeField] private Animator gunAnimator;
[SerializeField] private Transform barrelLocation;
[SerializeField] private Transform casingExitLocation;
[Header("Settings")]
[Tooltip("Specify time to destory the casing object")] [SerializeField] private float destroyTimer = 2f;
[Tooltip("Bullet Speed")] [SerializeField] private float shotPower = 500f;
[Tooltip("Casing Ejection Speed")] [SerializeField] private float ejectPower = 150f;
public AudioSource source;
public AudioClip fireSound;
public AudioClip reload;
public Magazine magazine;
public AudioClip noAmmo;
public XRBaseInteractable socketInteractor;
public void AddMagazine(XRBaseInteractable interactable)
{
magazine = interactable.GetComponent<Magazine>();
source.PlayOneShot(reload);
}
public void RemoveMagazine(XRBaseInteractable interactable)
{
magazine = null;
}
public void Slide()
{
}
void Start()
{
if (barrelLocation == null)
barrelLocation = transform;
if (gunAnimator == null)
gunAnimator = GetComponentInChildren<Animator>();
socketInteractor.onSelectEntering.AddListener(AddMagazine);
socketInteractor.onSelectExiting.AddListener(RemoveMagazine);
}
public void PullTheTrigger()
{
if(magazine && magazine.numberOfBullet > 0)
{
gunAnimator.SetTrigger("Fire");
}
else
{
source.PlayOneShot(noAmmo);
}
}
//This function creates the bullet behavior
void Shoot()
{
magazine.numberOfBullet--;
source.PlayOneShot(fireSound);
if (muzzleFlashPrefab)
{
//Create the muzzle flash
GameObject tempFlash;
tempFlash = Instantiate(muzzleFlashPrefab, barrelLocation.position, barrelLocation.rotation);
//Destroy the muzzle flash effect
Destroy(tempFlash, destroyTimer);
}
//cancels if there's no bullet prefeb
if (!bulletPrefab)
{ return; }
// Create a bullet and add force on it in direction of the barrel
Instantiate(bulletPrefab, barrelLocation.position, barrelLocation.rotation).GetComponent<Rigidbody>().AddForce(barrelLocation.forward * shotPower);
}
//This function creates a casing at the ejection slot
void CasingRelease()
{
//Cancels function if ejection slot hasn't been set or there's no casing
if (!casingExitLocation || !casingPrefab)
{ return; }
//Create the casing
GameObject tempCasing;
tempCasing = Instantiate(casingPrefab, casingExitLocation.position, casingExitLocation.rotation) as GameObject;
//Add force on casing to push it out
tempCasing.GetComponent<Rigidbody>().AddExplosionForce(Random.Range(ejectPower * 0.7f, ejectPower), (casingExitLocation.position - casingExitLocation.right * 0.3f - casingExitLocation.up * 0.6f), 1f);
//Add torque to make casing spin in random direction
tempCasing.GetComponent<Rigidbody>().AddTorque(new Vector3(0, Random.Range(100f, 500f), Random.Range(100f, 1000f)), ForceMode.Impulse);
//Destroy casing after X seconds
Destroy(tempCasing, destroyTimer);
}
}