Appointments are not exported to other calendars in the ICall feed

Hello everybody,

I have installed:

Module: Date iCal
Plug-in: iCalcreator (v2.20.2) with only the files in the directory sites / all / libraries on the server:
-composer.json
-iCalcreator.class.php
-lgpl
-README
-releaseNotes-2.20.2
-summary
-using

As in

https://www.drupal.org/project/date_ical →

and

https://modulesunraveled.com/calendar/creating-ical-feed-visitors-can-su...

described.

Within Structure / Views, the calendar view looks like the attachment. The path of /calendar-node-field-date-ereignis/%/ical.ics is black!

If I now want to integrate the ics file into other calendars, the error message: "0 imported appointments" appears. These error messages appear in Google, Outlook, and other calendars.

Ask:
What files does the iCreator plug-in need to have for Date iCal to work? (Preferably a link to the zip folder.)
Is the black path within Structure / Views correct? (see above and attached picture)
Master question: Why does not the import or the synchronization work?

And:
"17. If events that you expect your feed to include are not appearing when it
gets consumed by a calendar app, check the Drupal permissions for your
event content type. If anonymous users can't view the event nodes, they
won't appear in your feed when it gets loaded by a calendar app."

Where (click instructions) I have to check the permissions?

Greetings
Phantomias1