Examine source code of Bulk Select Google Photos

{
  "manifest_version": 3,
  "name": "Bulk Select Google Photos",
  "version": "1.40",
  "description": "Select multiple photos on Google Photos with just one click and then bulk delete, download, archive, share etc.",
  "permissions": [
    "activeTab",
    "storage",
    "contextMenus"
  ],
  "action": {},
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://photos.google.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "icons": {
    "48": "assets/icon-48.png",
    "128": "assets/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{55e7d7d6-d1b0-45bb-833b-8c4124fe16e6}"
    }
  }
}