https://privatephotoviewer.com/

Its name can vary from one place to another depending on Android devices. You can open the privacy profile viewer apk file for installation after you have enabled the setting. This setting must be enabled before loading the instagram plus the apk files, including the privately-owned visualisation file apk, not downloaded from the Google Play store. You can see a warning that warns you that you are blocking your operation while attempting to Access some apk file without allowing the "Unknown Sources" settings. From this message box you can quickly find the configurations of the "Unknown sources."