How to receive short messages with four extension numbers?

The four-digit extension number can receive the following short messages:

1. Open the short message, enter "10690 163334" at the receiver's location, and then add the first 4 digits of the number, such as "10690 165438+".

2. Add "unsubscribe" at the end and click "Send".

It should be noted that this method can only temporarily close the SMS function, and it is recommended to contact the local Unicom customer service for consultation and unblocking.