How to "unfix" the header when scrolling

Hello, This is my website: http://annemariebulla.de/. I´m using herefore the free version of parallax frame theme. My question is: How can I "unfix" my header title and menu so it is no longer visible (I want it to disappear) while scrolling down? As an alternate solution (if it´s not possible to change that) - how do I create this following "effect": The fixed header title and menu lying first over my slider pictures and then suddendly placed in a black background box while scrolling down (as you can see it at the demo version => https://catchthemes.com/demo/parallax-frame/) Thanks a lot for your help! P.S.: Sorry for my bad english - hope you understand my questions ;)