Problems connecting Calendar to Lightning in Thunderbird

I’m attempting to add 2 calendars from a 3rd party hosted installation of Nextcloud. Neither of us can successfully connect our Nextcloud Calendars to Thunderbird via Lightning.

There is scant documentation for this and what exists isn’t up to the task. I found the Thunderbird setting to allow more than one calendar from a single host and switched that to true. It still doesn’t work.

Is there any documentation for both setting up your personal calendar and how to share your calendar and how to add someone else’s nextcloud calendar?

Please provide more information and details.
What have you tried so far, what URLs did you use to connect to the calendars?
Can you tell us anything about the Nextcloud instance regarding version, OS, HTTP(s)? Do you have SSH access to that server? If so, can you find any error messages in the logs?

I try to add my calendar to Thunderbird like always, but it seems like the option to add my password is suddenly missing.

I already successfully used the calendar in thunderbird, but I had removed in in Thunderbird and when I add it, I cannot find the place to add my password.

the url i try is the same as before:

I add it exactly like this:

In the next step the calendar is already added to Lightning, but deactivated immediately.

Where do I add the password, so Thunderbird can sync the calendar, or what am I doing wrong?