SUMMARY

In the Handbook for Kate under the chapter 'LSP Client Plugin' -> 'Configuration' the example states

{
        "servers":
        {
                "python":
                {
                        "command": ["pylsp_in_env"], ["%{Project:NativePath}"],
                        "root": "."
                }
        }
}

However Kate does not accept a Copy&Paste of this example. This seems to be the correct version

{
        "servers":
        {
                "python":
                {
                        "command": ["pylsp_in_env", "%{Project:NativePath}"],
                        "root": "."
                }
        }
}


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kubuntu 23.04 x86_64
(available in About System)
KDE Plasma Version: Plasma 5.27.4