The type or namespace name & # 39; Rigibody2D & # 39; was not found. What is the problem? [on hold]

using System.Collections;
using System.Collections.Generic;
with UnityEngine;

public class movement: MonoBehaviour
{
public Rigibody2D rb;
public Transform groundCheck;
public float groundCheckRadius;
public LayerMask whatIsGround;
private bool onGround;

// Start is called before the first frame update
void Start()
{

    rb = GetComponent();




}

// Update is called once per frame
void Update()
{

    rb.velocity = new Vector2(1, rb.velocity.y);
    onGround = Physics2D.OverlapCircle(groundCheck.position, groundCeckRadius, whatIsGround);

    if (Input.GetMousseBuutonDown(0) && onGround)
    {
        rb.velocity = new Vector(rb.velocity.x, 3);