,Roll-A-Ball ball isn't moving

I am using Unity 2019.4.17f1. I copied what she did in the tutorial but the ball doesn't move when I enter play mode. Am I missing something?

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.InputSystem;
 
 public class PlayerController : MonoBehaviour
 {
 
     public float speed = 0;
 
     private Rigidbody rb;
 
     private float movementX;
     private float movementY;
 
     // Start is called before the first frame update
     void Start()
     {
         rb = GetComponent<Rigidbody>();
     }
 
 
     void OnMove(InputValue movementValue)
     {
         Vector2 movementVector = movementValue.Get<Vector2>();
 
         movementX = movementVector.x;
         movementY = movementVector.y;
     }
 
     void FixedUpdate()
     {
         Vector3 movement = new Vector3(movementX, 0.0f, movementY); //f = this is a float value
 
         rb.AddForce(movement * speed);
     }
 
 }