If you are not able to download UpNote from the Microsoft Store, you can download the installer for Windows app here. This installer is still new so Windows might warn you that it's not a common download, you just need to bypass the warning and run the installer.
Please note that if your computer has already installed UpNote from the Microsoft Store, you shouldn't use the installer above.
If you have installed AppImageLauncher, simply double click on the UpNote.AppImage file. AppImageLauncher will automatically change the AppImage file to executable, move it to the Applications folder and show the app icon correctly.