WSL2 requires Windows 10 version 2004 or higher (see the official documentation. Part of this guide is adapted and expanded from hubsian's guide on Emacs under WSL.
If you do not have WSL enabled already, follow the official installation instructions for WSL2. Once installed, make sure to have WSL2 installed with Ubuntu 20.04 by running the PowerShell as administrator and typing.
wsl -l -v