Custom Render Feature script template to be added to a LWRP Renderer. Drag 'n Drop this script to your project, write the desired rendering code. It now it's available to be added to a LWRP renderer by clicking on the + icon under renderer features in the Renderer inspector.

CustomRenderPassFeature.cs

using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.LWRP;

public class CustomRenderPassFeature : ScriptableRendererFeature
{
    class CustomRenderPass : ScriptableRenderPass
    {
        // This method is called before executing the render pass. 
        // It can be used to configure render targets and their clear state. Also to create temporary render target textures.
        // When empty this render pass will render to the active camera render target.
        // You should never call CommandBuffer.SetRenderTarget. Instead call <c>ConfigureTarget</c> and <c>ConfigureClear</c>.
        // The render pipeline will ensure target setup and clearing happens in an performance manner.
        public override void Configure(CommandBuffer cmd, RenderTextureDescriptor cameraTextureDescriptor)
        {
        }

        // Here you can implement the rendering logic.
        // Use <c>ScriptableRenderContext</c> to issue drawing commands or execute command buffers
        // https://docs.unity3d.com/ScriptReference/Rendering.ScriptableRenderContext.html
        // You don't have to call ScriptableRenderContext.submit, the render pipeline will call it at specific points in the pipeline.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
        }

        /// Cleanup any allocated resources that were created during the execution of this render pass.
        public override void FrameCleanup(CommandBuffer cmd)
        {
        }
    }

    CustomRenderPass m_ScriptablePass;

    public override void Create()
    {
        m_ScriptablePass = new CustomRenderPass();

        // Configures where the render pass should be injected.
        m_ScriptablePass.renderPassEvent = RenderPassEvent.AfterRenderingOpaques;
    }
    
    // Here you can inject one or multiple render passes in the renderer.
    // This method is called when setting up the renderer once per-camera.
    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        renderer.EnqueuePass(m_ScriptablePass);
    }
}