Examine source code of Accounts manager

{
  "name": "Accounts manager",
  "description": "Keep multiple Roblox accounts connected at the same time on just one browser.",
  "version": "1.0",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background/index.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.roblox.com/*"
      ],
      "js": [
        "popup.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "88.0",
      "id": "{9d530d4e-0c98-47cf-a480-9ebaf3e3e414}"
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "cookies",
    "webRequest",
    "webNavigation",
    "*://*.roblox.com/*"
  ],
  "browser_action": {
    "default_popup": "./popups/popup.html"
  },
  "icons": {
    "128": "./assets/icons/icon.png"
  }
}