In the development, the WeChat applet is used to send the SMS verification code, and the process used is summarized.
This is the complete flow chart of the first access, and you can basically access it according to the process.
Introduce signatures and templates:
When I first read this word, what did I base myself on? To read the introduction on the official website carefully, it is to add a personalized signature to the content of the short message, and then send it to the called mobile phone customer 
. Then the following content is the text message content template you created. You can create multiple signatures and templates, and you can write whichever one you choose to use. You can decide to use it according to when you write the code into the parameters.
other:
The first few are very simple, pay attention to when creating a SMS signature, pay attention to fill in the signature name according to the regulations, if you cannot fill in at will, the audit may not pass. Others are very simple to follow the access guidelines, and make up your own brain.
Note that when you report an error and test yourself, you will encounter:
Error is-business-limit-control-message
The error code refers to triggering the default flow control limit of SMS;
SMS verification code: use the same signature to send SMS verification code to the same mobile phone number, support 1/minute, 5/hour, 10/day. A mobile phone number can only receive 40 messages per day through the Alibaba Cloud SMS service platform. (If you are prompted for a business current limit when sending the verification code, it is recommended to adjust the interface calling time according to the above business)
SMS notification: Use the same signature and the same SMS template ID to send SMS notifications to the same mobile phone number, support 50 messages/day (if you are prompted for service current limit when sending SMS notifications, it is recommended to adjust the API calling time according to the above services )
Send according to the above restrictions, that is, no flow control will be triggered.