Javascript open new tab, and wait for it to close

Question

I want to open a new tab for a bank payment on my website using javascript, and without the main window navigating away,

when the user is back from the bank payment to a

Answer 1

The best approach with data transfer from the child window I found.

Parent code

window.open(url);
await new Promise(resolve => window.addEventListener('custom', resolve));

Child code

if(window.opener) {
  const customEvent = new CustomEvent('custom', { detail: {} });
  window.opener.dispatchEvent(customEvent);
  window.close();
}