random material

i need change material with render
var laserMaterial : Material;

function InitLaser() {
  
  laser = this.gameObject.AddComponent(LineRenderer);
  laser.SetWidth(0.5, 0.5);
  laser.SetVertexCount(2);
  laser.material = laserMaterial;  // this not change in game mod 
  laser.renderer.enabled = false;
  laser.useWorldSpace = true;

Try with

laser.renderer.material = laserMaterial;