Examine source code of Send to Mail

{
  "manifest_version": 2,
  "name": "Send to Mail",
  "version": "2.0.3",
  "description": "Share a URL directly from your browser via email",
  "homepage_url": "https://adrianistan.eu",
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "applications": {
    "gecko": {
      "id": "send-to-mail@divel",
      "strict_min_version": "55.0"
    }
  },
  "permissions": [
    "contextMenus",
    "activeTab",
    "tabs",
    "notifications"
  ],
  "background": {
    "scripts": [
      "background/mail.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/96.png"
  }
}