Error 404 unfound routes Actix-web

Could you provide an example on how to use it?

This is what I've got so far:

use actix_web::{web, App, HttpResponse, HttpServer, Responder, Result};
use actix_web::http::{StatusCode};


async fn index() -> impl Responder {
    HttpResponse::Ok()
    .content_type("text/html; charset=utf-8")
    .body("

    <h1>Home</h1>
    ")
}

async fn index2() -> Result<HttpResponse> {
    Ok(HttpResponse::build(StatusCode::OK)
        .content_type("text/html; charset=utf-8")
        .body("<h1>Rofl</h1>"))
}

async fn rofl() -> Result<HttpResponse> {
    Ok(HttpResponse::build(StatusCode::OK)
        .content_type("text/html; charset=utf-8")
        .body("<h1 style='color: red;'>Rofl pagina</h1>"))
}

async fn not_found() -> Result<HttpResponse> {
    Ok(HttpResponse::build(StatusCode::OK)
        .content_type("text/html; charset=utf-8")
        .body("<h1>Error 404</h1>"))
}

#[actix_rt::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(|| {
        App::new().service(
        web::resource("/index.html").route(web::get().to(index))


    )
    .default_service(
        web::route().to(not_found)
    )
        //Way to bind unfound pages to errro 404 page


    })
    .bind("127.0.0.1:8087")?
    .run()
    .await
}

How do. I make multiple routes inApp::new().service()? Now it's only working for index.html.
And the default_service is just returning a blank page instead of a customized Error 404-message.

Edit:
Got it working with the following code:

use actix_web::{web, App, HttpResponse, HttpServer, Responder, Result};
use actix_web::http::{StatusCode};


async fn index() -> impl Responder {
    HttpResponse::Ok()
    .content_type("text/html; charset=utf-8")
    .body("

    <h1>Home</h1>
    ")
}

async fn about() -> Result<HttpResponse> {
    Ok(HttpResponse::build(StatusCode::OK)
        .content_type("text/html; charset=utf-8")
        .body("<h1>About</h1>"))
}

async fn not_found() -> Result<HttpResponse> {
    Ok(HttpResponse::build(StatusCode::OK)
        .content_type("text/html; charset=utf-8")
        .body("<h1>Error 404</h1>"))
}


#[actix_rt::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(|| {
        App::new()
                .service(web::resource("/index.html").route(web::get().to(index)))
                .service(web::resource("/about.html").route(web::get().to(about)))
    .default_service(
        web::route().to(not_found)
    )
        //Way to bind unfound pages to errro 404 page


    })
    .bind("127.0.0.1:8087")?
    .run()
    .await
}