Examine source code of LolHistory2

{
  "manifest_version": 2,
  "name": "LolHistory",
  "version": "2.0",
  "description": "Ajoute un bouton à la barre d'outils qui affiche des 10 dernières parties de votre compte League of Legends",
  "homepage_url": "https://github.com/tac1DEV/web-extensions",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "https://europe.api.riotgames.com/*",
    "tabs",
    "<all_urls>",
    "webRequest",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/icon-32.png",
    "default_title": "My league profile",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@LolHistory2",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}