Examine source code of Breathe – Box Breathing & Relaxation Timer

{
  "manifest_version": 3,
  "name": "Breathe – Box Breathing & Relaxation Timer",
  "version": "1.3.0",
  "description": "Box breathing app and guided breathing exercise timer. 4-7-8, coherent 5-5 and custom rhythms, sound cues, goals and streaks.",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png",
    "256": "icons/icon256.png",
    "512": "icons/icon512.png"
  },
  "permissions": [
    "storage",
    "sidePanel"
  ],
  "action": {
    "default_title": "Open Breathe",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "commands": {
    "open-sidebar": {
      "suggested_key": {
        "default": "Alt+Shift+B"
      },
      "description": "Open Box Breathing: Guided Breathing & Calm Timer"
    }
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ]
  },
  "side_panel": {
    "default_path": "sidebar.html"
  },
  "sidebar_action": {
    "default_title": "Breathe",
    "default_panel": "sidebar.html",
    "default_icon": "icons/icon48.png",
    "open_at_install": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "boxbreathing@conceptx.example",
      "strict_min_version": "115.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "short_name": "Breathe"
}