Examine source code of AniList Extras

{
  "manifest_version": 2,
  "name": "AniList Extras",
  "description": "Adds a few additional features to AniList.",
  "version": "1.2.0",
  "minimum_chrome_version": "60.0.3112",
  "icons": {
    "128": "icon128.png"
  },
  "permissions": [
    "https://anilist.co/*",
    "https://graphql.anilist.co/*",
    "https://api.jikan.moe/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://anilist.co/*",
        "https://myanimelist.net/*"
      ],
      "js": [
        "polyfill.js",
        "anilist-extras.user.js"
      ],
      "run_at": "document_start"
    }
  ]
}