There are two possibilities:
…\MSFS 2020\Official\OneStore\fs-base-ui-pages\html_ui\Pages\Profile
(which includes a “logbook” directory)
and the recommended “wgs”
…\Users\NAME\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\SystemAppData\wgs
But who knows for sure, there is also another with “settings” in it …
…\Users\NAME\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\Settings
I have backed up all three, and any other ones I find or are suggested!!