how can I make a 2d player face the direction it is moving?

Hello I am highly confused because i am trying to make my character face the direction it is moving (can face up, down, left, right, and all the diagonals) this is my code for my player

 using UnityEngine;
 
 /// <summary>
 /// Player controller and behavior
 /// </summary>
 public class PlayerScript : MonoBehaviour
 {
     /// <summary>
     /// 1 - The speed of the ship
     /// </summary>
     public Vector2 speed = new Vector2(50, 50);
 
     // 2 - Store the movement and the component
     private Vector2 movement;
     private Rigidbody2D rigidbodyComponent;
 
     void Update()
     {
         // 3 - Retrieve axis information
         float inputX = Input.GetAxis("Horizontal");
         float inputY = Input.GetAxis("Vertical");
 
         // 4 - Movement per direction
         movement = new Vector2(
           speed.x * inputX,
           speed.y * inputY);
 
     }
 
  void FixedUpdate () {
          Vector2 moveDirection = GameObject.rigidbody2D.velocity;
          if (moveDirection != Vector2.zero) {
              float angle = Mathf.Atan2(moveDirection.y, moveDirection.x) * Mathf.Rad2Deg;
              transform.rotation = Quaternion.AngleAxis(angle, Vector3.forward);
          }
      }
 }

and i keep getting the error " error CS0120: An object reference is required to access non-static member `UnityEngine.GameObject.rigidbody2D' " if you know how i can fix this and make my player face the direction its moving please help, Thanks in advance

P.S: I would normally add smiley faces but i don't think i can add them P.P.S: I am also new to this so a detailed explanation would be helpful... Thanks.