InvoiceShelf/app/Http/Middleware/TrustProxies.php

<?php

namespace InvoiceShelf\Http\Middleware;

use Illuminate\Http\Middleware\TrustProxies as Middleware;
use Illuminate\Http\Request;

class TrustProxies extends Middleware
{
    /**
     * The trusted proxies for this application.
     *
     * @var array
     */
    protected $proxies;

    /**
     * The current proxy header mappings.
     *
     * @var array
     */
    protected $headers =
        Request::HEADER_X_FORWARDED_FOR |
        Request::HEADER_X_FORWARDED_HOST |
        Request::HEADER_X_FORWARDED_PORT |
        Request::HEADER_X_FORWARDED_PROTO |
        Request::HEADER_X_FORWARDED_AWS_ELB;

    /**
     * Get the trusted proxies.
     *
     * @return array|string|null
     */
    protected function proxies()
    {
        $this->proxies = env('TRUSTED_PROXIES', '*');

        return $this->proxies;
    }
}