How to set "fit to page width" when convert calc file to pdf in headless mode?

When I try to convert headless to pdf some files are wider to A4 and pdf file is 2 pages instead of 1 page as original calc file.

“Fit to page width” is not a “conversion” operation: it is editing the document (formatting it). Conversion does not involve editing, so you can’t do that using --convert-to.

But see this discussion.