I followed the tutorial of microsoft

I set the CMAKE_TOOLCHAIN_FILE of my local variable.

Yet it still hint that

"Add the installation prefix of xxx to CMAKE_PREFIX_PATH or set xxx_DIR"

And I set the CMAKE_PREFIX_PATH in CMakePresets.json:

{
    "version": 2,
    "configurePresets": [
        {
            "name": "default",
            "generator": "Visual Studio 17 2022",
            "binaryDir": "${sourceDir}/build",
            "cacheVariables": {
                "CMAKE_TOOLCHAIN_FILE": "<ROOT>/vcpkg/scripts/buildsystems/vcpkg.cmake",
                "CMAKE_PREFIX_PATH": "<ROOT>/vcpkg/packages/jsoncpp_x64-windows/share/jsoncpp"
            }
        },
        {
            "name": "release",
            "inherits": "default",
            "description": "Release configuration",
            "hidden": false,
            "cacheVariables": {
                "CMAKE_BUILD_TYPE": "Release"
            }
        },
        {
            "name": "debug",
            "inherits": "default",
            "description": "Debug configuration",
            "hidden": false,
            "cacheVariables": {
                "CMAKE_BUILD_TYPE": "Debug"
            }
        }
    ]
}

Now it compiled.