Examine source code of SimpleNotes

{
  "manifest_version": 3,
  "name": "SimpleNotes",
  "version": "1.5",
  "description": "A simple notes extension built with React.",
  "icons": {
    "16": "icons/note-16.png",
    "32": "icons/note-32.png",
    "48": "icons/note-48.png",
    "64": "icons/note-64.png",
    "128": "icons/note-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "SimpleNotes-id2@SimpleNotes.com"
    }
  },
  "action": {
    "default_popup": "index.html"
  },
  "permissions": [
    "storage"
  ]
}