Examine source code of Keychain Passwords for macOS

{
  "name": "Keychain Passwords for macOS",
  "version": "1.2.2",
  "description": "Use your passwords stored on iCloud Keychain® right from Firefox.",
  "author": "Aurélien",
  "manifest_version": 3,
  "action": {
    "default_icon": {
      "16": "./images/logo-16.png",
      "32": "./images/logo-32.png"
    },
    "default_popup": "./popup.html"
  },
  "icons": {
    "16": "./images/logo-16.png",
    "32": "./images/logo-32.png",
    "128": "./images/logo-128.png"
  },
  "permissions": [
    "storage",
    "nativeMessaging",
    "activeTab",
    "scripting",
    "clipboardWrite"
  ],
  "optional_permissions": [
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "options_ui": {
    "page": "./settings.html",
    "open_in_tab": false
  },
  "background": {
    "scripts": [
      "./background.js"
    ]
  },
  "web_accessible_resources": [
    {
      "resources": [
        "/in_page.html",
        "/in_page.js",
        "/in_page.js.map"
      ],
      "extension_ids": [
        "*"
      ],
      "matches": [
        "*://*/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "apple-passwords-firefox-extension@apple.com"
    }
  }
}