In the Process Configuration Tab, I have created my own attribute for a type of workitem. But, in this workitem, I can not assign some attributes to required.
That's located under Team Configuration > Operation Behavior > Save Work Item where you first select the role you want to configure in the top pane and can then configure Required Properties as one of the preconditions in the bottom pane.
Dashboards and work items are no longer publicly available, so some links may be invalid. We now provide similar information through other means.
Learn more here.
