You cannot simply download a single APK from Uptodown called "Minecraft 1.16.5 Java for Android." That file does not legally exist.
To run this specific version, you should use an unofficial launcher available on platforms like Uptodown or the Google Play Store. 1. Download a Compatible Launcher
PojavLauncher is a free, open-source app that runs the actual Java Edition on Android. It supports versions from old alphas up to 1.20+.