Open the "Downloads" or "Files" app on the device and install the APK. You may need to enable "Allow from this source" .
is not a single application; rather, it is a username or a developer alias associated with a specific FRP bypass tool (often named "Zaggar FRP Tool" or bundled with other Android utilities). The "zaggarxyz+frp+install" search query typically refers to: zaggarxyz+frp+install