Enable a justification field when the expense item exceeds the limit amount

Summary:

How to enable a justification field when the expense item exceeds the limit amount?

Content (please ensure you mask any confidential information):

Hello,

How can i enable a justification field when the expense item exceeds the limit policy amount ?

Thanks,

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

24C

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