KOrganizer error

When I test the connection for Korganizer I am getting this error " An error occurred: There was a problem with the request. Resource not found (404)."

I have followed the instructions here Synchronizing with KDE Kontact — Nextcloud latest User Manual latest documentation
Using an app password generated in the admin console. I have tried putting both my internal ip as the host and my dyndns address which works well for file uploads and sync. Not sure where I have gone wrong? Any help would be appreciated.