Examine source code of Save To Google Photos

{
  "manifest_version": 3,
  "name": "save-to-google-photos",
  "description": "Save web images to Google Photos by right click",
  "version": "1.0.1",
  "background": {
    "scripts": [
      "background/authorize.js",
      "background/context_menu.js",
      "background/storage.js",
      "background/upload.js",
      "background/toast.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_scripts/toast.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "save-to-google-photos@g.kg"
    }
  },
  "permissions": [
    "contextMenus",
    "storage",
    "identity",
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "icons": {
    "48": "icons/icon@48.png",
    "96": "icons/icon@96.png"
  }
}