Hiding navbar when scrolling (Semplice wordpress)


Staff member
I am using the semplice theme on wordpress to build my portfolio website. In the theme I am able to add CSS and JS coding. I would like to make my navbar dissapear when I scroll down and reappear when I scroll up.

I have found coding that should do this, however, it does not work and it does not look like coding which were suggested by semplice for other features. Unfortunately, semplice wont help in providing custom coding anymore.
I have been searching the whole afternoon on an answer. Does anyone have any experience with this? All suggestions are very welcome!!

Thanks in advance!