Can I use an app lock to protect my Second Phone Number app?

Yes, you can! Here's how to enable it:

1. Open the Second Phone Number app.
2. Tap the Gear icon in the top left corner of the Messages or Make a Call screen. This takes you to the Settings page. 
3. Scroll down in the Settings page and look for Require Passcode.
4. Toggle the switch next to the App Lock option to on. You can slide or tap the right side of the switch.
5. You can use Touch ID available on your device.

Now, whenever you or someone else tries to open the Second Phone Number app,it will require your passcode or biometric authentication (Touch ID) before granting access.

Remember:

• Choose a strong and unique passcode for added security.
• Consider enabling additional security options like Touch ID.

Tip: Regularly update the app to ensure you have the latest security features and bug fixes.