Mandatory resume in Refer a Candidate

Summary:

I have used TDE to make Resume mandatory in Refer a Candidate form but it doesn't work.

Content (please ensure you mask any confidential information):

I have used TDE to make Resume mandatory in Refer a Candidate form but it doesn't work. How do I make it mandatory to upload a resume when referring a candidate?

Version (include the version you are using, if applicable):

23D

Code Snippet (add any code snippets that support your topic, if applicable):