const cloud = require('wx-server-sdk')

const fs=require('fs')

const {Wechatpay, Formatter} = require('wechatpay-axios-plugin')

const cert = fs.readFileSync('./apiclient_cert.pem', 'ascii')

const prikey = fs.readFileSync('./apiclient_key.pem', 'ascii')

cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV }) // 使用当前云环境

exports.main = async (event, context) => {

  const wxContext = cloud.getWXContext()

  const wxpay = new Wechatpay({    

    mchid: '16********72',// 商户号

    // 商户证书序列号

    serial: '41217B61*****************C2D771C',

    // 商户API私钥 PEM格式的文本字符串或者文件buffer

    privateKey: prikey,

    certs: {

      //平台证书序列号

      '38******************A74': cert,

    },

    secret: 'fa*****************************36a',

    merchant: {

      cert: cert,

      key: prikey,

    },

  })

  return wxpay.v3.transfer.batches.post({

    appid: 'w**********44',

    out_batch_no:"3f19*********************ea22",

    batch_name:"test",

    batch_remark:'测试一下',

    total_amount:10,

    total_num:1,

    transfer_detail_list:[

      {

        out_detail_no:'kakatf001',

        transfer_amount:3,

        transfer_remark:'测试3分',

        openid:wxContext.OPENID,

        user_name:'名字'

      }

    ]

  }).then(res=>{

    console.log(res.data)

    return res

  })

  .catch(({response: {status, statusText, data}}) => console.error(status, statusText, data))

}

执行后报错

"{\"code\":\"PARAM_ERROR\",\"message\":\"HTTP header缺少微信支付平台证书序列号(Wechatpay-Serial)\"}"