invoiceninja/app/Http/Middleware/PhantomSecret.php

<?php
/**
 * Invoice Ninja (https://invoiceninja.com)
 *
 * @link https://github.com/invoiceninja/invoiceninja source repository
 *
 * @copyright Copyright (c) 2020. Invoice Ninja LLC (https://invoiceninja.com)
 *
 * @license https://opensource.org/licenses/AAL
 */

namespace App\Http\Middleware;

use Closure;

class PhantomSecret
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {

        if( config('ninja.phantomjs_secret') && $request->has('phantomjs_secret') && (config('ninja.phantomjs_secret') == $request->input('phantomjs_secret')) )
        {
            return $next($request);
        }

            return redirect('/');

    }

}