alipay.data.bill.balance.query是支付宝商家账户当前余额查询接口；目前调用该接口返回 ISV权限不足
完整返回：

{"body":"{"alipay_data_bill_balance_query_response":{"code":"40006","msg":"Insufficient Permissions","sub_code":"isv.insufficient-isv-permissions","sub_msg":"ISV权限不足，建议在开发者中心检查签约是否已经生效，解决办法详见：https:\/\/docs.open.alipay.com\/common\/isverror"},"sign":"VUa9MsGGWluXRmPoOm1SPNBzMHEFXN4VTlWEyuSd+m1Z+12LAMM4ZTSYgSaHu5X5MAVTpeUn5WTgu4OU55cWpSJyWfHnDjVf2Aw6Sd8w2//GI3BD7GxBWMoWVnuZM0sngOqmk4wD/Wvd9R5HZgCukCMWxHV+yCJUKWnGf2l3v9k="}","code":"40006","errorCode":"40006","msg":"Insufficient Permissions","params":{},"subCode":"isv.insufficient-isv-permissions","subMsg":"ISV权限不足，建议在开发者中心检查签约是否已经生效，解决办法详见：https://docs.open.alipay.com/common/isverror","success":false
}

通过询问客服，该接口还没对外开放

后续可关注开放平台通知。

之所以写这篇文章，是因为通过https://docs.open.alipay.com/common/isverror自查了原因，然后没有得到答案，网上博客又没有直接说明原因的。所以给后面的老铁接入时不浪费时间。