Examine source code of peepoCozy

{
  "manifest_version": 2,
  "name": "peepoCozy",
  "version": "1.0.0",
  "description": "Allows you to customize Twitch's video player: zoom and pan.",
  "icons": {
    "32": "icons/1.png",
    "64": "icons/2.png",
    "96": "icons/3.png",
    "128": "icons/4.png"
  },
  "content_scripts": [
    {
      "js": [
        "main.js"
      ],
      "matches": [
        "*://*.twitch.tv/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0a40d2c0-8f3d-4388-96f8-c58a9b6d14eb}"
    }
  }
}