Wechat cannot receive SMS verification code. What happened?

Wechat can't receive SMS verification code, which may be a network problem.

According to the official help center of WeChat, the SMS verification code of WeChat was sent by the mobile phone operator. If you don't receive the SMS verification code, it may be because of unstable cell phone signal or network connection problems. Mobile phone number entered incorrectly or changed; The SMS service of the mobile phone operator is out of order.