How to Uninstall Ubuntu 20.04 from WSL Windows 10?

I have Windows 10 (build 19042.1110) installed on my PC, and I wanted to install Ubuntu 20.04 using WSL (Windows Subsystem for Linux). So I enabled the WSL. However, I've not used the Microsoft Store to download Ubuntu: I downloaded the distribution directly from here (the .appx file)

Then, I followed these instructions and everything went fine. I created an account with password on Ubuntu, and did the updates/upgrades with apt get update and apt get upgrade.

Then I wanted to uninstall the distribution, but now I can't find it in the app&features panel nor in the start menu. If I search for "ubuntu" or "linux" on the start menu, I find nothing. I think this is due to the fact that I've not used the Microsoft Store.

How can I uninstall the distribution? I'd like to go back to how things were before installing Ubuntu. I've thought of using a system restore point, but I think this is unnecessary.

I'm pretty much a newbie in this area, so thank you for your help.

UPDATE:

I've run the command wsl --list --verbose to check and I got this:

 NAME STATE VERSION
* Ubuntu-20.04 Stopped 1

While the command Get-AppxPackage | Where-Object { $_ -like "*Ubuntu*" } didn't output anything.

Also, I found this, don't know if that's my case. However, the same page in my native language suggests using lxrun /uninstall /full for builds before the 1709 (16299) build, while for later builds it suggests using the Remove-AppxPackage cmdlet (which I don't know the sintax of).

(Sorry for the late update, thank you for your patience)

UPDATE 2:

I've used wslconfig /unregister Ubuntu-20.04 and everything went fine. I also reinstalled Ubuntu from Microsoft Store and uninstalled it from Apps & Features, and everything went fine. So thank you guys!

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