Help! My projectile velocity is not working..

Hi there. I am making a 2D platformer game and I can't solve why my projectile doesn't move when instantiated. It is stuck at the player's hand and immediately disappear.

In my player controller script:

      // projectile
      public Transform firePoint;
      public GameObject projectile      
          
      if(Input.GetKeyDown(KeyCode.X))
       {
            Instantiate(projectile, firePoint.position, firePoint.rotation);
       }

FirePoint is the position of the player's hand and Projectile is my projectile gameobject.

And I attach this script to my projectile:

       public float speed;
          // Use this for initialization
          void Start () {
          
          }
          
          // Update is called once per frame
          void Update ()
          {
              GetComponent<Rigidbody2D>().velocity = new Vector2(speed, GetComponent<Rigidbody2D>
              ().velocity.y);
          }
      
          void  OnTriggerEnter2D(Collider2D other)
          {
              Destroy(gameObject);
          }
 

When I press X, The projectile just appear and disappear immediately, but doesn't transform to right.

However when I put one of the projectile by itself in the scene, it works perfectly fine. The projectile will move towards right. Why is that so??? Thanks for help!