调用wx.requestPayment失败原因

小程序中执行统一下单成功后调用 wx.requestPayment，真机中“WeChat Pay”的Toast一闪而过，

1. errMsg:"requestPayment:fail"

2. err_code:2

3. err_desc:"Unable to verify signature"

1. errMsg:"requestPayment:fail"

2. err_code:2

3. err_desc:"支付验证签名失败"

模拟器中显示二维码

问题可能是那些原因？