Download the APK file of the application to your smartphone, this can be done via a short link https://diagzone.com/get-apk

On Android 7 and below:
1. In any file manager, click on the APK file.
2. In the "Installation blocked", warning window, click "Settings".
3. In the settings window that opens, find the item "Unknown sources" and activate the slider.
4. In the confirmation window, click "OK".
5. Go back to the APK file and click "Install".

On Android 8 and above:
1. In a file manager or browser, click on the APK file.
2. In the warning window, click "Settings".
3. In the settings window that opens, activate the "Permission for this source" slider or "Allow installation of applications".
4. Go back and click "Install".