Examine source code of Refresh All Tabs Plus

{
  "manifest_version": 3,
  "name": "Refresh All Tabs Plus",
  "version": "1.1.0",
  "description": "Refresh all tabs instantly or sequentially, plus auto-refresh a single tab on a timer. Includes cache bypass option.",
  "browser_specific_settings": {
    "gecko": {
      "id": "refresh-all-tabs-plus@milchhahn.github.io",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "tabs"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Refresh all tabs",
    "default_icon": {
      "16": "icons/icon_16.png",
      "32": "icons/icon_32.png",
      "48": "icons/icon_48.png",
      "64": "icons/icon_64.png",
      "128": "icons/icon_128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/icon_16.png",
    "32": "icons/icon_32.png",
    "48": "icons/icon_48.png",
    "64": "icons/icon_64.png",
    "128": "icons/icon_128.png"
  }
}