Posterboard, Limit # of events option not visible

Hi,
I need to limit the amount of events in the posterboard view for our shows page so that the repeating events don’t show too far in the future. This is Especially important if we only have a month or two of events filled out.

I’ve read in several places that I can got to settings > add-ons >extended views, and then write the limit.

However, this option isn’t showing up for me. Any thoughts why this field isn’t visible?