Examine source code of Partsbox Print Button

{
  "manifest_version": 3,
  "name": "Partsbox Print Button",
  "description": "Print entities to label directly from Partsbox web UI.",
  "version": "0.2",
  "permissions": [],
  "host_permissions": [
    "*://*.partsbox.io/*",
    "*://*.partsbox.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.partsbox.io/*",
        "*://*.partsbox.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icon.png",
    "48": "icon.png",
    "128": "icon.png"
  },
  "action": {
    "default_icon": {
      "16": "icon.png",
      "32": "icon.png",
      "48": "icon.png",
      "128": "icon.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "partsbox-print-ff@ceres-c.it"
    }
  }
}