Files won’t show up in iCloud Drive, because we sync using a hidden iCloud data store. You should see that there is data in iCloud though, if you go to the manage data area in System Preferences for iCloud. Agenda should be there, and have data.
If your iCloud Drive is turned on, it should be syncing. If it is actively uploading, you will see the cloud flash top-right in the window.
One way to confirm that data really is in iCloud would be to move aside your local data, and see if the data downloads again to fill up your local Agenda app. I don’t really recommend this, but if you are paranoid, you could try it:
- Ensure you are confident everything is synced up
- Quit Agenda
- In Finder, choose Go > Go to Folder
- Drag the folder
WRBK2Z2EG7.group.com.momenta.agenda.macos to your Desktop
- Launch Agenda and wait for it to sync up
If the data all comes back, you don’t need to do anything more. If there is a problem, you can always put back the folder on your Desktop, which contains your data.