1. Network connection problem: There is a problem with the network connection of the user equipment, and the verification code short message will not be sent to the user's mobile phone normally.
2. The server load is too high: the server carries a large number of requests or traffic, and the system can't process all the verification code sending requests in time, which leads to the sending failure.
3. Wrong or invalid mobile phone number: the mobile phone number provided by the user is wrong or has been deactivated, and the verification code SMS cannot be sent successfully.
Verification code is a security mechanism used to verify the user's identity or confirm the user's operation. It is a combination of a series of numbers, letters or symbols generated by a system or an application, and delivered to users in different forms.