Examine source code of Ntfy

{
  "manifest_version": 2,
  "name": "Ntfy",
  "version": "3.0",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "notifications",
    "storage",
    "*://*/*"
  ],
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bd164690-d145-43ed-ba0b-8a0b370001ac}"
    }
  }
}