Setting the position of linerenderer

Questions & Answers
1

I am making an fps and am using a raycast too shoot, obviously these are invisible so i tried using a linerenderer to see where you’re shooting. how do i make it that the line appears from the centre of the screen to where the shot has gone and then disappear after a second. this is what i have at the moment. at the moment the linerenderer is in the middle of my scene and the other point goes to where i shoot.
Script
using System.Collections;
using UnityEngine;

public class PlayerShoot : MonoBehaviour
{
    public PlayerWeapon weapon;

    [SerializeField]
    private Camera cam;

    [SerializeField]
    private LayerMask mask;

    public LineRenderer lr;

    void Start()
    {
        if (cam == null)
        {
            Debug.LogError("PlayerShoot: No camera referenced!");
            this.enabled = false;
        }

        lr = GetComponent<LineRenderer>();
        
    }

    void Update()
    {
        if (Input.GetButtonDown("Fire1"))
        {
            Shoot();
        }
    }
     void Shoot()
    {
        RaycastHit _hit;
        if (Physics.Raycast(cam.transform.position, cam.transform.forward, out _hit, weapon.range, mask))
        {
            //We hit something
            if (_hit.collider)
            {
                Debug.Log("Hit for " + weapon.damage);

                EnemyHealth enemyHealth = _hit.transform.gameObject.GetComponent<EnemyHealth>();
                enemyHealth.currentHealth -= weapon.damage;

                lr.SetPosition(1, _hit.point);
            }
        }
    }
}
2

That is what the Trail Renderer is for.