Examine source code of Email Tracker Blocker

{
  "manifest_version": 3,
  "name": "Email Tracker Blocker",
  "version": "1.0",
  "description": "Prevent senders from knowing when you've opened their emails by blocking email tracking pixels and hidden trackers.",
  "icons": {
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{123e4567-e89b-12d3-a456-526614174000}"
    }
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "activeTab"
  ],
  "host_permissions": [
    "*://mail.google.com/*",
    "*://outlook.live.com/*",
    "*://*.yahoo.com/*",
    "*://mail.protonmail.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "128": "icons/icon128.png"
    }
  }
}