Pick up and object with a Rigidbody,Pickup object with Rigidbody and hold it

I'm trying to get it so that the character can pick up a cube, that they then can jump on while still holding. But I can't find a way to do that. Here's the script I currently have: using System.Collections; using System.Collections.Generic; using UnityEngine;

public class MoveObjectScript : MonoBehaviour { public GameObject item; public GameObject tempParent; public Transform guide;

 // Start is called before the first frame update
 void Start()
 {
     item.GetComponent<Rigidbody>().useGravity = true;
 }

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

 void OnMouseDown()
 {
     item.GetComponent<Rigidbody>().useGravity = false;
     item.GetComponent<Rigidbody>().isKinematic = true;
     item.transform.position = guide.transform.position;
     item.transform.position = guide.transform.rotation;
     item.transform.parent = tempParent.transform;
 }

 private void OnMouseUp()
 {
     item.GetComponent<Rigidbody>().useGravity = true;
     item.GetComponent<Rigidbody>().isKinematic = false;
     item.transform.parent = null;
     item.transform.position = guide.transform.position;
 }

} ,