Examine source code of Restockalert.me

{
  "manifest_version": 3,
  "name": "Restockalert.me",
  "version": "1.0.0",
  "description": "Get restock alerts for sold-out products. Add the product you're looking at to Restockalert.me without leaving the store.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_title": "Restockalert.me",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "tabs",
    "alarms",
    "notifications"
  ],
  "host_permissions": [
    "https://app.restockalert.me/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://app.restockalert.me/*"
      ],
      "js": [
        "content-session-sync.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "exclude_matches": [
        "https://app.restockalert.me/*"
      ],
      "js": [
        "content-page-flag.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@restockalert.me",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "authenticationInfo",
          "browsingActivity"
        ]
      }
    }
  }
}