midasPay一直报 errcode:40101 errmsg:"mp_sig missing"错误

明明传了mp_sig了

而且用了同样的签名方法取getbalance接口数据没问题

url: https://api.weixin.qq.com/cgi-bin/midas/sandbox/pay?access_token=11_aD4_sX6a1VehVOjl6kIY_wtfmFH7DuVDUYGxqgMYnhoE_HCR_Fyi7wQbt30ZTxQyD0IxWGIYS3LyeIZwU3FRkD3-w8T_oXt_pb0s_MJemGiBdQ7xfEEBEZ1EwQ02naBr8osXuomHrYtGZhHFIXCgABAMBG

post json: {"openid":"o8bIu5d4r-HaPwyNG9iU--NG8dDU","appid":"wxc1a356743b43384c","offer_id":"1450015803","ts":1531745801,"zone_id":"1","pf":"android","user_ip":"::ffff:127.0.0.1","amt":150,"bill_no":"BillNo_29","pay_item":"钻石","app_remark":"无","sig":"77bc4625396c2bb23e4b0a69a563fe8b0276da103e8f447eddc3286e7b2e798b","access_token":"11_aD4_sX6a1VehVOjl6kIY_wtfmFH7DuVDUYGxqgMYnhoE_HCR_Fyi7wQbt30ZTxQyD0IxWGIYS3LyeIZwU3FRkD3-w8T_oXt_pb0s_MJemGiBdQ7xfEEBEZ1EwQ02naBr8osXuomHrYtGZhHFIXCgABAMBG","mp_sig":"4b5f92e43f5998366cb31b86e380437e2dc7638731b07e135b53cb32514ad5d1"}

返回：{errcode:40101 errmsg:"mp_sig missing"}

求助啊！！！！！！

附:

签名方法

exports.midasPay = async (amt,bill_no,pay_item,app_remark,userId,req,callback)=>{

    let userIp = widgets.getClientIp(req);

    let uData = await controls.getUserBalanceData(userId);

    let accessToken = await getAccessToken(userId,uData.debug);

    let uri = configs.MidaspayEnv=='dev'?'/cgi-bin/midas/sandbox/pay':'/cgi-bin/midas/pay';

    let params = {

        openid:uData.openid,

        appid:uData.debug?configs.DebugAppId:configs.AppId,

        offer_id:MidasOfferId,

        ts:parseInt(new Date().getTime()/1000),

        zone_id:'1',