Problem with death in Unity 2D?

Question

C++ / C#

And so, there is a code for something that, when a Player collides with an object with the Enemy tag, he dies, and a script for respawn, well, the problem is that when a character collides with an object, he simply rests on it, there is a Circle on the object Collider2D.
Script(Death)
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerDeath : MonoBehaviour
{
private bool hasEntered;

private void onCollisionEnter2D(Collision2D other)
{

if (other.gameObject.CompareTag("Enemy") && !hasEntered)
{

Destroy(gameObject);
LevelManager.instance.Respawn();
}
}
}

Script(Respawn)
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class LevelManager : MonoBehaviour
{

public static LevelManager instance;

public Transform RespawnPoint;

public GameObject PlayerPrefab;

private void Awake()
{

instance = this;
}

public void Respawn ()
{

Instantiate(PlayerPrefab, RespawnPoint.position, Quaternion.identity);
}
}