π keep getting this error“参数类型'字符串|undefined'不能赋值给' string '类型的参数。类型“undefined”不能分配给类型“string”。ts（2345）string|当我试图创建一个新的条带对象时
我的STRIPE_SECRET_KEY在我的.env.local文件中正确声明

import Stripe from 'stripe';
import { NextApiRequest, NextApiResponse } from 'next';

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY, {
  apiVersion: '2020-08-27',
  // Replace with your desired Stripe API version
});

const handler = async (req: NextApiRequest, res: NextApiResponse) => {
  const { email } = req.body;
  try {
    const customer = await stripe.customers.create({
      email: email,
    });
    res.status(200).json({
      code: 'customer_created',
      customer,
    });
  } catch (error) {
    console.log(error);
    res.status(400).json({
      code: 'customer_creation_failed',
      error: error,
    });
  }
};

export default handler;