Examine source code of anon.li - Privacy by Default. Not by Request.

{
  "manifest_version": 2,
  "name": "anon.li",
  "description": "Create private email aliases and share end-to-end encrypted files from any page.",
  "version": "2.0.0",
  "short_name": "anon.li",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "homepage_url": "https://anon.li",
  "permissions": [
    "storage",
    "contextMenus",
    "activeTab",
    "clipboardWrite",
    "alarms",
    "https://anon.li/*"
  ],
  "optional_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "content_security_policy": "script-src 'self' 'wasm-unsafe-eval'; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@anon.li",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "anon.li",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "exclude_matches": [
        "*://anon.li/*",
        "*://www.anon.li/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}