the type or namespace name RigidBody2D could not be found

[Kadyn]

I've decided to make 2nd a platformr and I'm learning about eminence. Notice that the syntax screen c# is not even illuminated and then began to get a mistake: The type or namespace name 'RigidBody2D' could not be found (are you missing a using directive or an assembly reference? Though I kind of wrote it right and should work.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Hero : MonoBehaviour

{

[SerializeField] private float speed = 3f;

[SerializeField] private int lives = 3;

[SerializeField] private float JumpForce = 5f;
private RigidBody2D rb;
private SpriteRenderer sprite;

private void Awake()
{
    rb = GetComponent<RigidBody2D>();
    sprite = GetComponentinChildren<SpriteRenderer>();
}

private void Update()
{
    if (Input.GetButton("Horzintal"))
        Run();
}

private void Run()
{
    Vector3 dir = transform.right * Input.GetAxis("Horizontal");
    transform.position = Vector3.MoveTowards(transform.position, transform.position + dir, speed * Time.deltaTime);
}

}

[magpie]

Look at what I can't explain in detail, but it's because you didn't choose to open it, more accurately than open scruples. That's how to solve the problem:

In general, you go into your project in Unity, press the Edit-Power Preferences... ♪ That's where you choose External Tools and External Script Editor.