How to add password lock to Apple SMS?

The specific steps of this operation are as follows:

1. Open the "Settings" application of the mobile phone, and find and select the "Screen Usage Time" option.

2. On the "Screen Usage Time" page, select "Limited Communication" to enter.

3. In Restricted Communication, select During screen use, and then select Contacts Only.

4. In addition, you can lock the SMS through the settings in the Messages application. After entering the settings, select the information option, find and select information security or information privacy protection, and then turn on the encryption information function.