Native app is a 32-bit application that can be run on both 32- and 64-bit versions of Windows operating system, but it comes with 64-bit version of FFmpeg toolkit only. This is because the official FFmpeg website provides only 64-bit version of binaries for Windows.
To use Native app on 32-bit Windows you need to download 32-bit version of FFmpeg toolkit:
ffmpeg-4.3.1-x86.zip (ZIP archive, 106 Mb)
After you downloaded the archive, extract files ffmpeg.exe and ffprobe.exe and place them into the Native app installation directory. This directory is in your local AppData folder:
1) Press Win+R, enter %LOCALAPPDATA% and press Enter, or open folder like C:\Users\<user account>\AppData\Local where <user account> is the name of your local account and C: is the system drive
2) Go to Programs\Ant.com\Ant Video downloader
3) Replace ffmpeg.exe and ffprobe.exe with files that you extracted from ffmpeg-4.3.1-x86.zip archive
Note: if you uninstall Native app, the files you placed into Programs\Ant.com\Ant Video downloader won't be deleted, you will need to delete them manually as well.