Examine source code of OpenSea

{
  "manifest_version": 2,
  "name": "OpenSea",
  "description": "The largest marketplace for NFTs Create, buy, sell, and discover unique digital assets.",
  "version": "1.1.0",
  "icons": {
    "16": "images/icon-16.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.mozilla.org/*"
      ],
      "js": [
        "js/background.js"
      ]
    }
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "images/icon-16.png",
      "48": "images/icon-48.png",
      "128": "images/icon-128.png"
    },
    "default_title": "OpenSea",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "support@opensea.com"
    }
  }
}