Can't install an APK from OneDrive on Android

Installing an APK from the Google Drive app on Android works fine for me after setting Google Drive on the "Install from external sources" list under Security settings to 'yes'. But the Microsoft OneDrive app does not appear on the list (even though it is installed), so I can't set it to yes. When I tap on an APK in OneDrive it just downloads it, it does not install it. There is also no permission for the app to "Install unknown apps" under app settings. From the search references, I found OneDrive is included as a source from where an APK can be installed (sideloaded) and have not found any search reference indicating it is not, but I cannot get it to install from there. Have tried on three different Android devices. What am I missing? Can anyone here install an APK from OneDrive on Android?