how to make sprite player jump for a fixed distance

how to make sprite player jump for a fixed distance in unity 2d,when I have used the code bellow. The sprite moves to up ,it doesn't return back to the ground , I have added rigidBody2d(); Could you help me?

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class RunTest : MonoBehaviour 
 {
 
  public static bool jumpBool =false;
 
     
 
     public bool grounded            = true;
     public int jumpSpeed          = 1;
     
     void Start () {
         
     }
     
     // Update is called once per frame
     void Update () {
         if(Input.GetKey(KeyCode .Space))
         {
             if(grounded==true){
                 rigidbody2D.AddForce(Vector3.up *  1f);
                 grounded= false;
                 jumpBool = true;
             }
 
         }
     }
 }