FNA-VSCode-Template/project_name/.vscode/launch.json

{
    // Change "mono" to "clr" for 64-bit .NET Framework debugging on Windows.
    // (See: https://github.com/OmniSharp/omnisharp-vscode/wiki/Desktop-.NET-Framework)

    "version": "0.2.0",
    "configurations": [
        {
            "name": "Launch",
            "type": "mono",
            "request": "launch",
            "program": "${workspaceFolder}/bin/Debug/project_name.exe",
            "cwd": "${workspaceFolder}",
            "preLaunchTask": "Build (Debug)"
        },
        {
            "name": "Attach",
            "type": "mono",
            "request": "attach",
            "address": "localhost",
            "port": 55555
        }
    ]
}