Go to admin panel, Then Extensions → Templates. Select the template → select option tab → Then select layouts. By default Layouts will select default layout.
You need to select your layout override first because layout override depend page layout setting.
Select your layout which you want to change header type (because layouts only affected with selected layout override. For more information: https://bdthemes.com/support/knowledge-base/understanding-about-layout-of-warp-framework/ )
By default layout header type default will be selected, if you want change header type so you need to select Fixed/Sticky/Smart Sticky from below dropdown.
Then click save and close button for save your settings.