Currently the sickness reporting is only available to users with sickness enabled. Managers without sickness enabled are therefore not able to access the sickness reporting dialog to make sickness on behalf of others.
Thank you for your suggestion.
Managers may backfill sickness reports on behalf of employees.
This can be actioned by going to :
Management > Leave > Request History > Backfill > Select employee > Backfill sickness report on their behalf.