如何在IHP中自定义404？

-- ErrorController.hs
module Web.Controller.Error where

import IHP.ControllerPrelude

instance Controller ErrorController where
    beforeAction = setLayout defaultLayout

    action NotFoundAction = do
        render NotFoundView

data NotFoundView = NotFoundView

instance View NotFoundView where
    html NotFoundView = [hsx|
        <h1>404 Not Found</h1>
        <p>Sorry, the page you requested does not exist.</p>
        |]

-- routes.hs
instance FrontController WebApplication where
    ...
    controllers = 
        ...
        , parseRoute @ErrorController
        ...

-- Main.hs
main = do
    -- 进行其他设置...
    runRIO App {..} $ do
        let ?modelContext = db
        startWebServer port

-- Application.hs
instance CanRoute ErrorController where
    parseRoute' = do
        string "/error"
        action <- parseRoute'
        pure (ErrorController, action)

    dispatch' ErrorController = do
        let controller = ErrorController
        action <- requireAction
        case action of
            NotFoundAction -> autoRefresh do
                ensureResponseContainsStatus status404
                controller |> action