$invoiceForm = $oldInvoiceForm ?? $this->createForm(InvoiceProjectInvoiceType::class, $invoiceProject, [
        'action' => $this->generateUrl('invoice_edit', ['id' => $invoiceProject->getId()]),
    ]);

/**
 * @param Request $request
 * @param InvoiceProject $invoiceProject
 * @return Response
 * @Route("/{id}/edit/invoice", name="invoice_edit", methods="POST")
 */
public function editInvoice(Request $request, InvoiceProject $invoiceProject){

    $form = $this->createForm(InvoiceProjectInvoiceType::class, $invoiceProject);
    $form->handleRequest($request);

    if ($form->isSubmitted() && $form->isValid()) {
        $this->getDoctrine()->getManager()->flush();
        $this->addFlash("notice", "La config a bien été créée");
        return $this->redirectToRoute('invoice_show', ['id' => $invoiceProject->getId()]);
    }
    else{
        return $this->forward("ClientBundle:InvoiceProject:show", [
            'id' => $invoiceProject->getId(),
            'oldInvoiceForm' => $form
        ]);
    }
}

<form name="clientbundle_invoiceproject_invoice" method="post" action="/client/131/edit/invoice">
    <button type="submit" class="btn btn-secondary">Modifier les informations</button>
     </form>