I recharged rice coins with Unicom SMS. Why can't I get the verification code?

Unable to receive SMS or verification code for the following reasons: 1. You can check whether the mailbox is full first. If it is full, please delete some information. 2. If it is still not received after deletion, you can change the machine or card to see if it is a hardware factor; 3. After eliminating the above reasons, you can try to test whether it can be received in other places to see if it is the reason for the weak local signal. If the above problems do not exist, it may be related to the network function. It is recommended to contact local manual customer service to handle this problem.