I tried to print iframe document with this code.

  const printReport = () => {
    window.frames['integration_report'].focus();
    window.frames['integration_report'].print();
  };

But the browser printed the error code for the print function.

DOMException: Blocked a frame with origin "http://localhost:8082" from accessing a cross-origin frame.

I solved the problem by adding the cross origin authority to the sandbox. But I still wonder why this authority is needed to print dom.