To play/sound an octive higher than written the notation 8va is used, likewise, 8va basso is used for playing/sounding an octive lower.
Is there a way to notate 8va and 8va basso in NWC?
https://forum.noteworthycomposer.com/?topic=1501, https://forum.noteworthycomposer.com/?topic=3128 for starters