Document Library change the default name for the file upload

Hi All,

I have document library where users upload different files to this library

My Client asked to change the file upload default name (add a document) to New Upload Documents. 

When use click + add new document, the file upload box open. About the choose a file where it says add a document. Change the default name.

I did f12 and saw the title, but I couldn't make the change.

Thanks

Please see the picture.

Abenet