To print a score, select the Print button from the top left of your score's editor:
A window will appear to which you can choose your desired printing option.
"Print Full Score" will print a copy that shows every part in concert pitch.
"Print Individual Parts" (Noteflight Premium users only) will print an individual score for each instrument used in its respective transposition.
"Print Full Score and Individual Parts" will simultaneously print both of the described actions above.