QR Code Generator for Gmail

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "description": "Generate a QR code and insert it into the email when composing or replying",
  "version": "1.0.1",
  "manifest_version": 3,
  "name": "QR Code Generator for Gmail",
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "https://mail.google.com/*"
  ],
  "background": {
    "service_worker": "service-worker.js"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "19": "icons/19.png",
      "38": "icons/38.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "libs/jquery-3.2.1.min.js",
        "contentScript.js"
      ],
      "css": [
        "style.css",
        "libs/css/scope-bulma.min.css"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self';"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "*.js",
        "assets/*",
        "libs/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}