On Android device, navigate to 'Apps' > 'Settings' > 'Security', enable 'Unknown Sources', then tap 'OK' to agree to enable this setting. This will allow the installation of third party apps and standalone APKs.

The second way is to download the APK file to your computer, mount your phone's SD card in the computer (or connect the phone with the SD inserted in it to the computer via USB cable) and copy the APK file to the SD card, then insert the SD card in the phone and install the APK file from the SD card using an ...