Android may block unknown sources by default. Here is a safe install path for FamilyCall Guard.

  1. Open the official Download page on this website.
  2. Download the latest APK release.
  3. Allow install from your browser only for this one-time install.
  4. Open the APK and grant Call Log permission when prompted.
  5. Sign in / link the device to your parent account.

Always download from this official site to avoid tampered APKs.