In this page:
quota management is listed as a feature of the Files panel.
However, at least in WAC version 1809.5, I'm not able to access the quota management feature from "Files".
Where is it?
If you have the feature installed, you can manage the quota on the Volumes tab of the storage tool. If the feature is not installed, you can install it from here as well, but it will require a reboot before you can manage.
Brandon Williams commented
I am having the same issue - I do not see anywhere to adjust the quota.