On Windows Server 2019, WSL 1 is the only officially supported version.
WSL 2 requires Windows Server 2022 or later.
Use WSL 1 if You only need basic Linux tools and faster startup times. If You need enhanced compatibility with Linux software, then use WSL 2.
No, the wsl --install command won't work on Windows Server 2019 - this command is only available for Windows 10 and Windows 11.