Migrating and upgrading: how do I retain my calendar?

I was running Owncloud 8.2. I successfully migrated to NextCloud 9.0.58 but I’m seeing the following at https://example.com/owncloud/index.php/settings/apps?category=disabled for calendar, tasks and contacts:

This app cannot be installed because the following dependencies are not fulfilled:
ownCloud 8.2 or lower is required.

I understood that these were included in core now, but I don’t see them anywhere and this is what I use
How do I restore my calendars?

I read this Is this the correct ownCloud 8.2.3 > Nextcloud 10 migration path? but it seemed to imply that my calendars ad contacts would just be there, but they aren’t. I actually don’t see any calendar at all. There’s no option for it in the top left (just “Files” / “Activity” / “Gallery”). How do I access the calendar?

I feel like I’m missing something basic here.

Figured it out. When I updated all the way to NC 12, I was able to go to apps -> disabled apps and update calendar, contacts and tasks, and then enable them.