with code

• APPROVAL_REQUEST_NOT_FOUND
• APPROVAL_COMPLETED when approval request is already approved, rejected or abandoned
• DECISION_NOT_YET_ALLOWED when trying to take decision before previous step completion
• APPROVER_NOT_ALLOWED when user is not an approver in given approval request
• DECISION_ALREADY_TAKEN when approver is trying to modify already taken decision

with code

• APPROVAL_REQUEST_NOT_FOUND when approval request is not found