Where is the firewall of the old-age phone?

In the settings of the mobile phone. The method of setting the firewall is as follows: 1. Select dial. After entering the dialing page, click the function key on the far left of the mobile phone to select harassment interception. 2. Then click the Settings button in the upper right corner, and click the switch behind the harassment interception to turn on the interception function. 3. Choose to intercept strangers. After setting up, you can intercept incoming calls and text messages with blacklisted numbers.