Is it possible to install a microsoft certified appx without windows store and without sideloading?

Question

I need to support older windows versions, those which do not have sideloading enabled by default. Also, the application needs to be published as appx to support older versions.

The app is a desktop bridge converted application.

It will be distributed without the windows store, but a windows certification is possible.

Would a windows certified appx be possible to install without using the windows store, or is sideloading required for all apps that arent downloaded directly from the windows store, regardless of them beeing certified?

Answer 1

Sideloading must be enabled if you want to install app packages from any other source than the official Microsoft Store. Additionally the package must be signed using a trusted certificate

You can enable sideloading either manually on the device or by configuring a group policy (or by running a PowerShell script) as is described here