unity requirecomponent
using UnityEngine;// PlayerScript requires the GameObject to have a Rigidbody component
[RequireComponent(typeof(Rigidbody))]
public class PlayerScript : MonoBehaviour
{
Rigidbody rb; void Start()
{
rb = GetComponent<Rigidbody>();
} void FixedUpdate()
{
rb.AddForce(Vector3.up);
}
}