Require password for each application to install

Since I will be lending my phone to someone else, I want my phone to ask my Google account password (or alternative authentication) each time an app is installed. If I go to *Google Play* -> *Three bars menu* -> *Settings* -> *Require authentication for purchases*, the options are: 1. For all purchases through Google Play on this device. 2. Every 30 minutes. 3. Never. The first option seems to be what I am looking for. Nevertheless, I am not asked for any authentication for installing apps. **Can this be done? How?** Using a Samsung Galaxy J7, with Android 6.0.1.