Edit a UDF in Marketing Document Rows in Edit Mode

Hi,

I have a UDF in Marketing Document Rows.

After the document is added, if I navigate to that document, I am able to edit some of the Header fields (like Contact Person, Due Date, Document Date, etc.) and some fields in the Logistics and Accounting tabs, etc.

But the UDF in the Contents tab is disabled for editing.

How can I enable editing with or without the use of SDK?

Thanks.