Examine source code of Steam Account Switcher

{
  "manifest_version": 2,
  "name": "Steam Account Switcher",
  "version": "1.0",
  "description": "Easily switch between multiple Steam accounts and manage account-specific tasks.",
  "permissions": [
    "activeTab",
    "tabs",
    "*://store.steampowered.com/*",
    "*://steamcommunity.com/*"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon.png"
    }
  },
  "icons": {
    "48": "icons/icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3612ee9c-064b-4e8e-b917-5cf2346a32a6}"
    }
  }
}