When declining a job offer, Candidate should not be able to decline without providing a reason?

Clients Requirement:

When Rejecting a Job offer the Candidate should select the reason for declining the offer otherwise, he cannot proceed declining the offer.

Reason field should be made mandatory on Job offer decline page of Candidate.

Is this possible? I have checked all the latest documents on Oracle but could not find any solution.

Oracle Docs related info so far:

In the Implementing Recruiting doc 23A

Allow Candidate Reason and Comment on Withdraw to Yes has been mentioned which made the reason field and comments field to be visible on candidate Job offer decline page.

Information for making these attributes mandatory is not mentioned.