Examine source code of Hold On

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "Hold On",
  "description": "Pause before you scroll. Add friction to entertainment sites and reclaim your attention.",
  "version": "1.0.0",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "storage",
    "tabs",
    "webNavigation"
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "/hold.html"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "background": {
    "service_worker": "background.js"
  },
  "action": {
    "default_title": "Hold On",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  }
}