I have a document library to which I have added a Responsive form, with a field mandatory, so that the form pops up to have data entered when I add a new item.  The issue I am having is that the (SharePoint 2019) "Add a document" dialog is quite a bit narrower than the Responsive form designer, so the items on the form are all shown in a single column, rather than showing the items as I placed them on the form.  It even places the Save button above the Cancel button, instead of placing them in the same row (even though there would be enough space for these to be shown side by side).

Does anyone know how I could make the "Add a document" dialog wider to show the form more attractively?