How can I instantiate and sync a LineRenderer in multiplayer network?

Question

I am trying to make a laser that will be visible to all clients in a multiplayer networked game on Unity.

I've tried using a Command Attribute but that hasn't worked. I also found some ideas to use RpcClient but I am not quite sure how to implement that.

The code I'm using for the laser (I just run the method in Update) is:

public void CmdActivateLaser(bool laserState)
{
    if (laserState == false)
        return;


    pointer.SetPosition(0, transform.position);

    RaycastHit endCommand;
    if (Physics.Raycast(transform.position, transform.forward, out endCommand))
    {

        finalPos = new Vector3(0f, 0f, endCommand.distance);
        pointer.SetPosition(1, finalPos);

    }
    else
    {
        pointer.SetPosition(1, transform.forward * 500f);
    }
}