Examine source code of PNGTree Metadata Helper

{
  "manifest_version": 3,
  "name": "PNGTree Metadata Helper",
  "version": "1.4",
  "description": "Auto-fill metadata fields for PNGTree contributor uploads.",
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "pngtree-metadata-helper@localhost",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://contributors.pngtree.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}