Thanks for the video.
This is indeed not the expected behavior. I believe it’s connected to the fact that you’re using a stripped-down version of Windows without MS Store (LTSC, probably?).
Lookupper is a modern Windows 10/11 app distributed as an MSIX package, as recommended by Microsoft and the Windows App SDK. Therefore, there is no way for it to be installed via an .exe installer.
The only workaround I can recommend is to install a full version of Windows 10 or 11 using the original image from the Microsoft website.