How to Set Landscape Orientation and Enable "Fit Sheet on One Page"?

I'm using QXlsx version 1.5 and I'm trying to configure print settings for a worksheet. Specifically, I need to:

1. Set the page orientation to landscape.
2. Enable the "Fit Sheet on One Page" option (equivalent to Excel's Fit to 1 page wide by 1 page tall).

Any guidance or code examples would be greatly appreciated!
Thank you,
mar8us