App\Http\Controllers\QuoteController::approve PHP Method

    public function approve($invitationKey)
    {
        $invitation = Invitation::with('invoice.invoice_items', 'invoice.invitations')->where('invitation_key', '=', $invitationKey)->firstOrFail();
        $invoice = $invitation->invoice;
        $invitationKey = $this->invoiceService->approveQuote($invoice, $invitation);
        Session::flash('message', trans('texts.quote_is_approved'));
        return Redirect::to("view/{$invitationKey}");
    }