want to empty field based on previous state of filed using iftt.

[Manojkumar Yadav]

I have a fields

1) Draft(Radio Button)

    i) Save as Draft

    ii) Submit

2) ReviewerOutcome(Drop-Down)

   i)APPROVED

   ii)REJECTED

   iii) SENT BACK

I am using below IFTT to empty ReviewerOutcome field but not working

Event: onModified

Action to perform: Update Confiform Entry

Condition/Filter: Draft.label: Submit AND [entry._previousState.ReviewerOutcome]:[SENT BACK]

Parameter to set:

entryID=[entry.id]&ReviewerOutcome=[empty]