Below is a code block for myself the next time I need a launch.json file to enable debugging within VSCode using a Codeigniter4 project. Hope someone else also it useful.

It is extracted from this Youtube video:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Launch built-in web server",
            "type": "php",
            "request": "launch",
            "runtimeArgs": [
                "spark",
                "serve",
                "-dxdebug.mode=debug",
                "-dxdebug.start_with_request=yes",
                "-S",
                "localhost:8080"
            ],
            "env": {
                "XDEBUG_MODE": "debug",
                "XDEBUG_SESSION": "permsExample",
            },
            //"externalConsole": true,
            "program": "",
            "cwd": "${workspaceRoot}",
            "port": 9003,
            "serverReadyAction": {
                "pattern": "Development server \\(http://localhost:[0-9]+)\\) started",
                "uriFormat": "http://localhost:%s",
                "action": "openExternally"
            }
        }
    ]
}