Examine source code of GPro Sound

{
  "manifest_version": 2,
  "name": "gpro-sound",
  "version": "1.0",
  "content_scripts": [
    {
      "matches": [
        "https://www.gpro.net/*/racescreen.asp*"
      ],
      "js": [
        "inserter.js"
      ]
    }
  ]
}