If you have a phone with Android 14 (or higher I assume), you'll have to bypass normal installation with this guide: https://thedroidwin.com/app-not-installed-as-app-isnt-compatible-with-your-phone I used the 2nd method. I did a quick test but the vn works fine so far.
In a nutshell the latest OSs don't allow apps that are made for old Android versions. For whatever reason Android gives a vague error: "App not installed as app isn't compatible with your phone" if done by normal means.