In the tsconfig.json set

"sourceMap": true,

to generate mappings alongside with js-files from the TypeScript sources using the tsc command.
The launch.json file:

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "node",
            "request": "launch",
            "name": "Launch Program",
            "program": "${workspaceRoot}\\index.js",
            "cwd": "${workspaceRoot}",
            "outFiles": [],
            "sourceMaps": true
        }
    ]
}

This starts node with the generated index.js (if your main file is index.ts) file and the debugger in Visual Studio Code which halts on breakpoints and resolves variable values within your TypeScript code.

Create a Node.js debug configuration and use index.js as Node parameters.

Add ts-node to your TypeScript project:

npm i ts-node

Add a script to your package.json:

"start:debug": "ts-node --inspect=5858 --debug-brk --ignore false index.ts"

The launch.json needs to be configured to use the node2 type and start npm running the start:debug script:

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "node2",
            "request": "launch",
            "name": "Launch Program",
            "runtimeExecutable": "npm",
            "windows": {
                "runtimeExecutable": "npm.cmd"
            },
            "runtimeArgs": [
                "run-script",
                "start:debug"
            ],
            "cwd": "${workspaceRoot}/server",
            "outFiles": [],
            "port": 5858,
            "sourceMaps": true
        }
    ]
}

Add this script to your package.json:

"start:idea": "ts-node %NODE_DEBUG_OPTION% --ignore false index.ts",

Right click on the script and select Create 'test:idea'... and confirm with 'OK' to create the debug configuration:

Start the debugger using this configuration: