The name `PlatformerCharacter2D' does not exist in the current context

using UnityEngine;

[RequireComponent(typeof(PlatformerCharacter2D))]
public class Platformer2DUserControl : MonoBehaviour
{
	private PlatformerCharacter2D character;
	private bool jump;

	void Awake()
	{
		character = GetComponent<PlatformerCharacter2D>();
	}

	void Update ()
	{
		// Read the jump input in Update so button presses aren't missed.
		if (Input.GetButtonDown("Jump")) jump = true;
	}

	void FixedUpdate()
	{
		// Read the inputs.
		bool crouch = Input.GetKey(KeyCode.LeftControl);
		float h = Input.GetAxis("Horizontal");

		// Pass all parameters to the character control script.
		character.Move( h, crouch , jump );

		// Reset the jump input once it has been used.
		jump = false;
	}
}

Hi I got the sample assets on the store and imported the 2d folder and now it doesn’t recognise PlatformerCharacter2D. : was following this tutorial 1. How to make a 2D Platformer - Basics - Unity Tutorial - YouTube
i already got rid of this error [The name `CrossPlatformInput' does not exist in the current context - Questions & Answers - Unity Discussions] but it still won’t work.

Either the class is not in your Assets folder, or it’s in another namespace.