Fortunatelly creating a custom error pages in Laravel is not a rocket science.

You just need to create a new folder resources/views/errors/ and create new views with error code as part of their names.

Let's start with 404 Not Found error.

Just create a new view resources/views/errors/404.blade.php and add the following code.

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Bootstrap 5 404 Error Page</title>
        <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet">
    </head>
    <body>
        <div class="d-flex align-items-center justify-content-center vh-100">
            <div class="text-center">
                <h1 class="display-1 fw-bold">404</h1>
                <p class="fs-3"> <span class="text-danger">Opps!</span> Page not found.</p>
                <p class="lead">
                    The page you’re looking for doesn’t exist.
                  </p>
                <a href="index.html" class="btn btn-primary">Go Home</a>
            </div>
        </div>
    </body>
</html>

Similarly you can create rest of the error handling blade views for 403, 500, ... errors.

To test your newly created 404 error handling view, you need to start your application

php artisan serve

and open http://localhost/some-not-existing-url in your browser.