Examine source code of Phantom

{
  "manifest_version": 2,
  "name": "Phantom",
  "version": "222.1",
  "description": "Phantom (A crypto wallet reimagined for DeFi & NFTs) is your trusted companion for web3.",
  "browser_action": {
    "default_icon": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2223261b-7140-4a18-87bf-751843acf2fb}"
    }
  }
}