Simplified version of ScriptableRendererFeature

MyRendererFeature.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

namespace UnityEngine.Experimental.Rendering.Universal {
    public class MyRendererFeature : ScriptableRendererFeature {

        [System.Serializable]
        public class Settings {

            public bool isEnabled = true;
            [Range(0, 1)] public float intensity = 0.5f;

            public RenderPassEvent renderPassEvent = RenderPassEvent.AfterRenderingTransparents;

            public Target target = Target.Camera;
            public Material blitMaterial = null;
            public string textureId = "_BlitPassTexture";
        }

        public enum Target {
            Camera,
            Texture
        }

        public Settings settings = new Settings();
        RenderTargetHandle m_renderTargetTexture;

        MyRenderPass myRenderPass;

        public override void Create() {
            myRenderPass = new MyRenderPass(this.name, settings.renderPassEvent, settings.blitMaterial);
            m_renderTargetTexture.Init(settings.textureId);
        }

        public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData) {

            if(!settings.isEnabled || settings.intensity <= 0 || settings.blitMaterial == null)
                return;

            settings.blitMaterial.SetFloat("_Intensity", settings.intensity);

            RenderTargetIdentifier src = renderer.cameraColorTarget;
            RenderTargetHandle dest = (settings.target == Target.Camera) ? RenderTargetHandle.CameraTarget : m_renderTargetTexture;
            myRenderPass.Setup(src, dest);

            renderer.EnqueuePass(myRenderPass);
        }
    }

}