Ensure that your development server is running (npm start). Then press F5 or the green arrow to launch the debugger and open a new browser instance

react_launch.json

{
  "version": "0.2.0",
  "configurations": [
    // **********************************************************************
    // Go to the Run view ⇧⌘D and click on the gear button or Create a launch.json link to create a `launch.json``
    // debugger configuration file. 
    // Choose Edge: launch from the Select Environment dropdown list. 
    // This will create a launch.json file in a new `.vscode` folder in your project 
    // which includes a configuration to launch the website.
    // **********************************************************************
    {
      "name": "Chrome and VSCode",
      "type": "chrome",
      "request": "launch",
      "console": "integratedTerminal",
      "url": "http://localhost:3000",
      "webRoot": "${workspaceFolder}/src",
      "sourceMapPathOverrides": {
        "webpack:///src/*": "${webRoot}/*"
      },
    }
  ],

}