# General troubleshooting
1. It may be that you did not fill in your WeChat payment merchant number and payment key in the background WeChat settings;
2. The WeChat payment secret key you set must be "api security key", not "apiv3";
3. The set key length exceeds. WeChat stipulates that the secret key length is 32 bits. If you set more than 32 bits, WeChat will truncate and keep only the first 32 bits. Then the secret key you fill in in the factory background exceeds 32 bits, resulting in a secret key error;
4. When setting the secret key, only uppercase and lowercase letters, underscores, and numbers can be used. Never add special characters;
5. The merchant account for WeChat payment must either be applied for using the current mini program (you cannot just use WeChat payment); or you must perform MA authorization (for details, you can search Baidu: WeChat payment MA authorization);
6. Make sure that the APPID logged in on the WeChat development tool is the same as the APPID you configured in the background;
# FAQ
## Signature error
Backstage system settings-online payment-WeChat payment-edit, v2 secret key error, signature error only occurs in this case
## appid and mch_id do not match
[https://www.yuque.com/apifm/doc/zrui8q](https://www.yuque.com/apifm/doc/zrui8q)
## Development tools pay normally, but mobile phones cannot pay.
Shipping information synchronization function not connected to order management
1. `mp.weixin.qq.com` left menu, order management, order information entry, agree to access, fill in the order address and submit
If the address must be filled in to indicate that it is under review before it can be submitted, you can submit it for review, fill it in again, and then withdraw the review after filling it out.
If it is an angel children's clothing template, fill in the address `pages/order-details/index?payOrderNo=${product order number}`
2. In the left menu of `mp.weixin.qq.com`, WeChat payment, all WeChat payment merchant accounts associated with it must be in the authorized state. If they cannot be authorized, they must be deleted.
3. Log in to our backend, go to Mall Management - Order Settings - Edit - at the bottom, there is a switch to synchronize shipping information to WeChat Mini Program, which must be turned on.
## requestPayment:fail banned
[https://developers.weixin.qq.com/community/develop/doc/0000241942cf4834005394fb961800?highLine=vpferrMsg%253A%2522requestPayment.fail%2520banned%2522%257D] (https://developers.weixin.qq.com/community/develop/doc/0000241942cf4834005394fb961800?highLine=vpferrMsg%253A%2522requestPayment.fail%2520banned%2522%257D)
# In-depth investigation
_If the problem still exists after carefully checking the above, please follow the steps below to continue troubleshooting: _
Please check the network request and the complete json data returned by the api interface. According to experience, it may be caused by the following situations:
```plain
{code: 50000, msg: "The merchant account has not been authorized for this product. Please go to Merchant Platform > Product Center to check and try again"}
```
**Follow the above tips, log in to your WeChat payment backend (WeChat payment backend! Not the factory backend! Not the official account’s backend!), click on the product list, and activate the JSAPI collection function! **
# Ask for help
_If the above information cannot help you troubleshoot the problem, please bring the complete json data returned by the API interface and leave a message below, we will do our best to help you troubleshoot_
**Hope the above information can help you! **
**Thank you for your attention! **