How to make the flatpickr module scroll in a modal window?

Question

JavaScript

When I open the module https://flatpickr.js.org/ inside the modal window, the module itself scrolls fixed. But if you scroll the background itself, then it goes fine , if in a modal window, then it becomes fixed

. How can I do all this, so that it is normal there. At the same time, these fields are all arbitrary and it is difficult to find out their number, because the user himself can add such fields with the datepicker.