Why must fields to add an event be required?

When adding a new event via the Drupal Off-Canvas or a pop up model dialogue, the space of the form is limited. If displayed all fields, particular the long text field, the form would overlay.

Adding an event in a new page should not be affected.

So, this new feature won’t be considered.

Drupal provides a way to override a controller class. You can try that via a custom module.

@mingsong : do you have more info how to override a class? A link where to find an example?

- I use the full page view to add an event and not required fields are also not appearing.

If the new event was created by double clicking on a date in the calendar, this module just simply open a new page with the populated start date.
https://git.drupalcode.org/project/fullcalendar_view/-/blob/5.x/fullcale...

In this case, the page URL is something like '/node/add/article?start=2024-08-01&start_field=field_start&destination=/calendar', and there should be no field hidden. I would suggest have a look at other module or theme that hide the fields from your node edit page.

- Do you have more info how to override a class? A link where to find an example?

https://www.drupal.org/docs/drupal-apis/routing-system/altering-existing... →
https://drupal.stackexchange.com/questions/81362/how-do-i-alter-the-rout...

I use the button below the calender and then I go to /fullcalendar-view-event-add?entitiy=node&bundle=... where the not required fields not appears. When I remove $element['#access'] = FALSE; then it is working.
Thx for info about altering classes!