下午好，
我正在实现一个支付处理器，我需要带来相应的支付ID，这是自动生成的后端。
我用PHP创建了前端和数据库，在前端用JS向后端请求数据，但是我无法得到ID。
我尝试通过脚本将php中的id传递给一个js变量，然后用localstorage将其发送到前端，但没有成功。

$payment->transaction_amount = (float) $form_data['transaction_amount'];
$payment->token = $form_data['token'];
$payment->description = "Pago";
$payment->installments = (int)$form_data['installments'];
$payment->payment_method_id = $form_data['payment_method_id'];
$payment->issuer_id = (int)$form_data['issuer_id'];

$payer = new MercadoPago\Payer();
$payer->email = $form_data['payer']['email'];
$payer->identification = array(
    "type" => $form_data['payer']['identification']['type'],
    "number" => $form_data['payer']['identification']['number']
);
$payer->first_name = $form_data['cardholderName'];
$payment->payer = $payer;

$payment->save();

$response = array(
    'status' => $payment->status,
    'status_detail' => $payment->status_detail,
    'id' => $payment->id
);

$id = ($response['id']); //separating the id

echo ($id); // id to bring to the frontend

JS：

<script>
payId = "<?php echo $id ?>"; //pass the id from php to js
payId = localStorage.setItem('idPago', payId); //I save it with localstorage
</script>

前端：

const renderCardPaymentBrick = async (bricksBuilder) => {
            const settings = {
                initialization: {
                    //tenes que fijarte si esto esta en pesos o
                    amount: price, // monto a ser pago

                    // preferenceId: "" // where i need to bring the id
                },
                callbacks: {
                    onReady: () => {
                        // callback llamado cuando Brick esté listo
                    },
                    onSubmit: (cardFormData) => {
                        cardFormData['cardholderName'] = document.getElementsByName("HOLDER_NAME")[0].value;
                        // ejemplo de envío de los datos recolectados por el Brick a su servidor
                        return new Promise((resolve, reject) => {
                            fetch("./api/mp.php", {
                                    method: "POST",
                                    headers: {
                                        "Content-Type": "application/json",
                                    },
                                    body: JSON.stringify(cardFormData)
                                })
                                .then((response) => {
                                    console.log(response);
                                    resolve();
                                })
                                .catch((error) => {
                                    console.log(error);
                                    // tratar respuesta de error al intentar crear el pago
                                    reject();
                                })
                        });
                    },
                    onError: (error) => {
                        // callback llamado para todos los casos de error de Brick
                    },
                },
            };
            const cardPaymentBrickController = await bricksBuilder.create('cardPayment', 'cardPaymentBrick_container', settings);
        };

很抱歉，有些注解是西班牙语的，但重要的是前端开头的preferenceId。
我很感激你帮忙！非常感谢。