Attribute Mapping in Manage Contracts Approval Rule

Hello, we are trying to set up an approval rule for the Employment Contract extension reason field. However, when setting up the rule, the transaction does not pass through the Worker's Proposed Contract.Extension Reason attribute. We wanted to know if the field might be mapped to some other attribute. We tried creating a rule with a condition for all the transactionApprovalRequest.attributenumbers but that did not give us the attributes stored in these numbers when reviewing the transaction log file.