Why can't I receive the verification code of Longgang Lesson 1 SMS?

SIM card failure, mobile phone arrears, poor signal.

1. When users use their mobile phones, they can't receive short messages, which is caused by SIM card failure, telephone arrears or poor signal, and Longgang can't receive the SMS verification code for the first lesson.

2. Users can insert the SIM card into other mobile phones to check whether they can receive the verification code. If the communication of third-party servers is delayed, they need to move to a place where the signal is stable, or they can continue to use the phone bill because the phone is in arrears.