Examine source code of PullTube Extension

{
  "manifest_version": 2,
  "name": "PullTube",
  "version": "1.2.0",
  "description": "Sends current page to PullTube app on MacOS or its download later list",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "pt_16x16.png",
    "default_title": "Open With Pulltube",
    "theme_icons": [
      {
        "dark": "pt_16x16_white.png",
        "light": "pt_16x16.png",
        "size": 32
      }
    ]
  },
  "commands": {
    "XUOpenCurrentSite": {
      "description": "Send current page to PullTube",
      "suggested_key": {
        "default": "Ctrl+Shift+P",
        "mac": "MacCtrl+Shift+P"
      }
    },
    "XUOpenCurrentSiteLater": {
      "description": "Download current page later with PullTube",
      "suggested_key": {
        "default": "Ctrl+Shift+L",
        "mac": "MacCtrl+Shift+L"
      }
    }
  },
  "permissions": [
    "contextMenus",
    "tabs",
    "activeTab",
    "theme"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{86badee5-8e68-4450-a924-a88885e1b201}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}