Add perlion vlaues together?

Unity Engine
1

Hi so I have setup a quad that gets texured by perlin noise. now I just want to clean the perlin noise by adding multiple perlin noise layers together. My problem is I don’t know how it works.
Here is my code:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class TextureGen : MonoBehaviour
{
    [Range(1, 1024)]
    public int resolution = 256;
    public float refinement = 0.1f;
    Texture2D texture;
   
    // Start is called before the first frame update
    void Awake()
    {
        texture = new Texture2D(resolution, resolution, TextureFormat.RGB24, true);
        texture.name = "Procedual Texture";
        GetComponent<MeshRenderer>().material.mainTexture = texture;
        FillTexture();
    }

    // Update is called once per frame
    public void FillTexture()
    {
        //float stepsize = 1f/resolution;
       
        if(texture.width != resolution)
        {
            texture.Resize(resolution, resolution);
        }
       
        for(int y = 0; y < resolution; y++)
        {
            for(int x = 0; x < resolution; x++)
            {
                texture.SetPixel(x, y, new Color(0f, Mathf.PerlinNoise(x * refinement, y * refinement), 0f));
            }
        }
       
        texture.Apply();
    }
}
2

When talking about noise layers, do you mean octaves? That’s a common technique to mix together various noises with varying amplitudes and frequencies. Take a look here: