Increase list under "Open Recent"

[Phil V]

I am using Okular Version 1.9.3
How do I increase the list of Documents under "Open Recent"
from the default ten (10) ?

I tried
kwriteconfig5 --group RecentDocuments --key MaxEntries 40

and logged out of kde and back in again, but it did not seem to make a
difference.

Best regards!
PV