Examine source code of Checker Plus for Google Drive™

{
  "browser_specific_settings": {
    "gecko": {
      "id": "checkerplusforgoogledrive@jasonsavard.com"
    }
  },
  "name": "Checker Plus for Google Drive",
  "description": "__MSG_description__",
  "version": "15.0",
  "homepage_url": "https://jasonsavard.com?ref=homepage_url&ext=drive",
  "background": {
    "scripts": [
      "js/common.js",
      "js/checkerPlusForDrive.js",
      "js/offscreen.js",
      "js/difflib.js",
      "js/diffview.js",
      "js/background.js"
    ]
  },
  "action": {
    "default_icon": "images/buttonIcons/default.png",
    "default_title": "Checker Plus for Google Drive™",
    "default_popup": "popup.html?source=toolbar&setVia=manifest"
  },
  "icons": {
    "16": "images/icon19.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "default_locale": "en",
  "permissions": [
    "alarms",
    "idle",
    "storage",
    "notifications",
    "contextMenus",
    "activeTab",
    "identity"
  ],
  "optional_permissions": [
    "*://*.googleusercontent.com/*",
    "https://docs.google.com/"
  ],
  "manifest_version": 3,
  "web_accessible_resources": [
    {
      "resources": [
        "options.html",
        "contribute.html"
      ],
      "matches": [
        "https://*.jasonsavard.com/*",
        "https://checkout.stripe.com/*",
        "https://www.paypal.com/*",
        "https://nowpayments.io/*"
      ]
    },
    {
      "resources": [
        "oauth2callback.html"
      ],
      "matches": [
        "https://accounts.google.com/*",
        "https://*.jasonsavard.com/*"
      ]
    }
  ]
}