How does Xiaomi check how much traffic is used?

There are two commonly used methods to find out how much traffic Xiaomi's mobile phone model uses. The first is a function that comes with Xiaomi's mobile phone, which is to open the phone housekeeper settings and the package we should have, and then we can query the traffic we consume in the current month, and then we can set a traffic threshold. The second is to send a text message directly to our mobile phone, or call the operator directly, and then check how much traffic is used, or receive a text message from the operator to see if it is used.