How to fix "Cannot find runtime 'nodemon' on PATH. Make sure to have 'nodemon' installed."?

I try to debug nodejs app with nodemon on visual studio code so that I can auto restart the debugger each time I save my code. However, it just kept poping up this error message when I run my debugger on visual studio code: "Cannot find runtime 'nodemon' on PATH. Make sure to have 'nodemon' installed"

I have tried to reinstall visual studio code, reinstall nodemon globally and locally.

Here is my launch.json file:

"version": "0.2.0",
  "configurations": [
    {
      "type": "node",
      "request": "launch",
      "name": "nodemon",
      "runtimeExecutable": "nodemon",
      "program": "${workspaceFolder}/app.js",
      "restart": true,
      "console": "integratedTerminal",
      "internalConsoleOptions": "neverOpen"
    }
  ]```