Examine source code of Social Share Preview

{
  "name": "Social Share Preview",
  "version": "0.0.0.9",
  "manifest_version": 2,
  "permissions": [
    "activeTab",
    "declarativeContent",
    "storage",
    "https://*/*",
    "http://*/*"
  ],
  "description": "See how your website looks when shared on Social Media!",
  "homepage_url": "https://placid.app",
  "browser_action": {
    "default_title": "Social Share Preview"
  },
  "icons": {
    "16": "icons/icon-active16.png",
    "48": "icons/icon-active48.png",
    "128": "icons/icon-active128.png"
  },
  "default_locale": "en",
  "background": {
    "scripts": [
      "src/bg/background.js"
    ],
    "persistent": true
  },
  "web_accessible_resources": [
    "css/social-image-preview-iframe.css"
  ]
}