Examine source code of Share Backported

{
  "description": "This extension reimplement the share feature with Container support and over 14+ social networks",
  "manifest_version": 2,
  "name": "Share Backported",
  "version": "2.1.15",
  "icons": {
    "16": "icon-dark.svg",
    "24": "icon-dark.svg",
    "48": "icon-dark.svg",
    "96": "icon-dark.svg"
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "icon-dark.svg",
      "24": "icon-dark.svg",
      "48": "icon-dark.svg",
      "96": "icon-dark.svg"
    },
    "theme_icons": [
      {
        "dark": "icon-dark.svg",
        "light": "icon-light.svg",
        "size": 16
      },
      {
        "dark": "icon-dark.svg",
        "light": "icon-light.svg",
        "size": 24
      },
      {
        "dark": "icon-dark.svg",
        "light": "icon-light.svg",
        "size": 48
      },
      {
        "dark": "icon-dark.svg",
        "light": "icon-light.svg",
        "size": 96
      }
    ],
    "default_title": "Share",
    "default_popup": "modal/modal.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Alt+Y"
      }
    }
  },
  "page_action": {
    "default_icon": "icon-dark.svg",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "permissions": [
    "tabs",
    "storage",
    "cookies",
    "activeTab",
    "management",
    "contextualIdentities",
    "https://www.reddit.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1bab54e2-6c60-4ee1-88f7-52b1df77924f}"
    }
  }
}