Don’t be so pessimistic! We’re here to help you out—that’s why the Wick forums were even made.
I can tell you instead!
So, when you export your project as a single HTML file, Wick embeds your project as a data URI. If one would want to recover their file, they’d have to find that ultra-long URI, select it, copy it, and paste it into their browser. Their browser would then download the file as… “file”, and you can rename it to something like yourfilenamehere.wick.
This is how I remember it, though, I don’t usually recover Wick files often, and when I do I use @Hamzah_Alani’s converter.