Problems retrieving CalDAV Url from Nextcloud calendar app

Dear all,
I heard quite about NextCloud so i decided to install and get more into it, unfortunately i am very new. I installed Nextcloud 25.0.2 version running with PHP 8.1.13, when i installed the calendar app that i need for some specific automatization tasks i will use later. Fisrt problem i faced is that in calendar settings, clicking the option copy the CalDAV Url in your clipboard, i get a specific error message, saying is impossible copying the url in the clipboard.

This is the screenshot:

I searched everywhere for errors but it seems the browser console is ok, and then after a while i decided to add in config.php file the debugging option enable

 $CONFIG = array(
  'debug' => true,
 //rest of config file.

in nextcloud log file it seems to be all ok, no relevant errors.

What i am missing?
I have an idea, i didn’t mention before that i am using nextcloud in a local enviroment in a docker container(for now just for testing, later i will deploy eveything), without a custom domain with particolar ssl certificates encryption associated. Could it be the problem that isn’t allowing me copy the url?

Thanks a lot!