Examine source code of Calm Background Sounds

{
  "manifest_version": 3,
  "name": "Calm Background Sounds",
  "version": "1.0.0",
  "description": "Play calming ambient sounds while you browse. Choose from rain, ocean waves, or white noise to help you focus and relax.",
  "homepage_url": "https://calmnervousystem.com",
  "permissions": [
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "sounds/*.mp3"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "calm-background@calmnervousystem.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}