0. In NextCloud web calendar, press the three dots (**···) next to the calendar (your own or a colleagues) which you'd like to have in Thunderbird and press **Copy private link**

1. In Thunderbird calendar view, right-click in the empty space below your calendar and selecting **New Calendar...**

3. Choose the **CalDAV** option, paste the private link from the first step in the **Location** text field (leave the username blank) and press the **Next** button

4. Give your calendar a name, sticking to the name used in NextCloud to the extent practical, and save the dialog, and you're done!