The alt-t/alt-T commands download PDF files of the current page or full score.

Saving the currently displayed page

Pressing alt-t will download a PDF containing the currently displayed music in the VHV webpage. If the graphical music is wider than it is high, the downloaded PDF will be in landscape mode; otherwise, the PDF will be in portrait orientation.

Files will be downloaded wherever your browser saves downloaded files. Here is a demonstration of typing alt-t to save a file and then opening the downloaded PDF in another tab in the web browser.

save currently viewed notation.
Saving currently viewed notation to a PDF and then opening PDF.

Saving the entire score to a PDF file

Pressing alt-shift-T will download a PDF containing the entire score. The layout in VHV will not be used but rather the music will be typeset for letter-sized paper in portrait orientation:

save currently viewed score.
Saving currently viewed score to a multi-page PDF.