Drag 2D Sprite by Touch

Im able to drag and drop gameobjects by touch. Well, here is an example script from the internet:

using UnityEngine; using System.Collections;

public class Drag2 : MonoBehaviour { private float dist; private bool dragging = false; private Vector3 offset; private Transform toDrag;

  void Update()
  {
      Vector3 v3;
 
      if (Input.touchCount != 1)
      {
          dragging = false;
          return;
      }
 
      Touch touch = Input.touches[0];
      Vector3 pos = touch.position;
 
      if (touch.phase == TouchPhase.Began)
      {
          RaycastHit hit;
          Ray ray = Camera.main.ScreenPointToRay(pos);
          if (Physics.Raycast(ray, out hit) && (hit.collider.tag == "Circle"))
          {
              Debug.Log("Here");
              toDrag = hit.transform;
              dist = hit.transform.position.z - Camera.main.transform.position.z;
              v3 = new Vector3(pos.x, pos.y, dist);
              v3 = Camera.main.ScreenToWorldPoint(v3);
              offset = toDrag.position - v3;
              dragging = true;
          }
      }
      if (dragging && touch.phase == TouchPhase.Moved)
      {
          v3 = new Vector3(Input.mousePosition.x, Input.mousePosition.y, dist);
          v3 = Camera.main.ScreenToWorldPoint(v3);
          toDrag.position = v3 + offset;
      }
      if (dragging && (touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled))
      {
          dragging = false;
      }
  }

} Problem: i have no idea how to do that with Sprites which are 2D and have a Rigidbody2D and Collider2D. The above scripts needs mesh which is not for 2D. Any solutions ?