Why did the SMS prompt fail?

First, check whether your SMS center number is set incorrectly:

The SMS center number of China mobile users is:

+86 1380 three-digit area code 0 (four-digit area code) 500.

(For example, the number of Beijing SMS Center is +86 13800 100500, Shenzhen SMS Center is +86 1380075500, Chongqing SMS Center is +86 13800230500, and Shanghai is+866500.

The number of users' SMS center of China Unicom is irregular. Here are two examples:

Chongqing:+8613010831500;

Beijing:+8613010112500

If it is not from the above two places, you can call the local Unicom customer service phone number 100 10 for consultation.

However, if you can't send it even if the number of the SMS center is set correctly, I suggest you call the customer service phone of the operator you use. The mobile number is 1860, and the Unicom number is 100 10. Let them solve it for you, there should be no problem.

If it can't be solved, you have to consider whether it's your mobile phone.