How to set NULL in Return Date as default value in Return to Receipts screen

Summary:

How to set NULL in Return Date as default value in Return to Receipts screen?

Content (please ensure you mask any confidential information):

End user want "Return Date" to be set as blank due to avoid entering sysdate as the original default value.

I tried to modify the defualt values in page composer but I can not reach the solution myself.

Please someone give an advice..

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

25A

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