Default number of bars in score setup

Sorry if this is a stupid question (new to NOTION). How can I increase the number of blank bars available when setting up a new score? It seems that I am unable to import a full wave file without it being truncated by the default number of bars of blank score created by 'score setup'? I'm also finding this a problem when simply writing to the score - I have to insert new bar lines to create the extra bars. There must be a way of extending the blank score by a set number of bars.
Any advice greatly appreciated.
Ian G
Any advice greatly appreciated.
Ian G