Page top margin vs. print range

.odt in use, Writer 7.6 for Linux
Only PDF-Printer present on system

If to lower the page top margin to 0,63cm or less (page custom style dialog) the warning pops up: margin settings out of print range.
Nowhere I can find print range setting, neither the LO/Writer Options, nor printer Printer settings while document open, nor in document properties.
I come to this point because the reference document has page headers pretty located in page top margin area. It is hard by some mystique reason to achieve the same effect in Writer. Hence the idea was to give page top margin less height, but the limit is 0,63cm. I doubt this document to be ever printed to paper.
Printer name “Generic Printer”, printer was possibly installed by LO as no other app can find it in this form.

Where to find print range settings?

This print area is defined by the selected printer. You cannot change it.
It is simply predetermined by the design of the respective printer brand/type.
If you don’t print to this printer but export the document as a PDF, you can also ignore this message or confirm it negatively.
Try it out.