Examine source code of Tabka

{
  "manifest_version": 3,
  "version": "1.4.3",
  "name": "Tabka",
  "description": "Tabka allows you to organize browser tabs and improve efficiency in accessing key resources.",
  "short_name": "Tabka",
  "action": {
    "default_title": "Tabka",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/logo/favicon_16.png",
      "32": "assets/logo/favicon_32.png",
      "48": "assets/logo/favicon_48.png"
    }
  },
  "web_accessible_resources": [
    {
      "resources": [
        "assets/js/*.js",
        "assets/css/*.css"
      ],
      "matches": [
        "*://*/*"
      ]
    }
  ],
  "background": {
    "type": "module",
    "scripts": [
      "/js/background.js"
    ]
  },
  "host_permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "all_frames": true,
      "js": [
        "js/inject.js"
      ],
      "matches": [
        "*://*/*"
      ]
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/get-metadata-preview.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "permissions": [
    "contextMenus",
    "unlimitedStorage",
    "storage",
    "tabs",
    "activeTab",
    "identity",
    "webRequest",
    "webRequestBlocking",
    "tabGroups",
    "bookmarks"
  ],
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Alt+Shift+D",
        "mac": "Command+Shift+D"
      },
      "description": "Open Tabka"
    },
    "region-select": {
      "suggested_key": {
        "default": "Alt+Shift+S",
        "mac": "Command+Shift+S"
      },
      "description": "Select region for bookmark cover"
    }
  },
  "optional_permissions": [
    "history",
    "tabGroups",
    "*://to/*",
    "<all_urls>"
  ],
  "icons": {
    "16": "assets/logo/favicon_16.png",
    "48": "assets/logo/favicon_48.png",
    "128": "assets/logo/favicon_128.png"
  },
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "58.0",
      "id": "tabka@vornashev.com"
    }
  },
  "chrome_settings_overrides": {
    "homepage": "newtab.html"
  }
}