Since the transition to 2021.11, the integration and reconfiguration buttons in the integration menu no longer respond. I thought 2021.12 was going to fix the problem, but no.
Do you have any idea of the problem, I have tested several browsers, nothing works.
Have you tried doing a cacheless reload/refresh to see if that helps? (Or just clear all site data in your browser for your HASS install.) Shift+Reload or Ctrl+Reload does this on many popular browsers, but see here for more: