Examine source code of vSecure

{
  "manifest_version": 3,
  "name": "vSecure",
  "description": "This browser extension provides a simple and efficient way to secure text strings. It allows you to encrypt text.",
  "version": "3.0.0",
  "action": {
    "default_icon": {
      "16": "./images/icon16.png",
      "32": "./images/icon32.png",
      "48": "./images/icon48.png",
      "128": "./images/icon128.png"
    },
    "default_title": "vSecure - Securing text string easier.",
    "default_popup": "index.html#form"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "iacido@gmail.com"
    }
  }
}