Examine source code of TCVS Extension

{
  "manifest_version": 2,
  "name": "TCVS Extension",
  "version": "2.4.0",
  "description": "Enables secure CORS-compliant communication between Corelation Keystone credit union systems and U.S. Treasury Check Verification",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "tabs",
    "https://tcvs.fiscal.treasury.gov/*"
  ],
  "optional_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "browser_action": {
    "default_title": "TCVS Extension",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    "inject.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "tcvs-extension-v2@ttcu.tech"
    }
  }
}