code: @Override
      public NutMap pay_jsapi(String key, WxPayUnifiedOrder wxPayUnifiedOrder) {
          NutMap map = this.pay_unifiedorder(key, wxPayUnifiedOrder);
          NutMap params = NutMap.NEW();
          params.put("appId", wxPayUnifiedOrder.getAppid());
          params.put("timeStamp", String.valueOf((int) (System.currentTimeMillis() / 1000)));
          params.put("nonceStr", R.UU32());
          params.put("package", "prepay_id=" + map.getString("prepay_id"));
          params.put("signType", "MD5");
          String sign = WxPaySign.createSign(key, params);
          params.put("paySign", sign);
          return params;
      }
docs: 微信公众号JS支付
  
  @param key
  商户KEY
  @param wxPayUnifiedOrder
  交易订单内容
  @return