Examine source code of hosthash

{
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "58.0a1",
      "id": "hosthash@example.com"
    }
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_action": {
    "browser_style": true,
    "default_title": "hosthash",
    "default_popup": "hosthash.html",
    "default_icon": {
      "48": "icon48.png",
      "96": "icon96.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "description": "Generates Base64 encoded Sha256 hash with your salt of currently active tabs hostname (example https://www.google.com/search?client=firefox-b-d&q=test+search hostname is www.google.com).",
  "homepage_url": "https://hosthash.example.com",
  "manifest_version": 2,
  "name": "hosthash",
  "version": "1.0"
}