Munk WordPress theme comes with 2 primary header layouts which you can select from the Theme Customizer.
Primary header displays your site logo, title and primary navigation.
Primary Header can be customized from Customizer >> Header >> Primary Header
Primary Header Layout
This dropdown will let you select primary header layout. Munk by default comes with 2 Header layout.
Enable Primary Menu
You can enable or disable primary navigation menu using this toggle in case you do not want to show the menu on your site.
Primary Header Padding
You can adjust the top and bottom padding of the primary header using this option. By default top and bottom padding is set to 10px. You can change it if you would like to have a different padding for your primary header.
Bottom Border and Color
The bottom border slider lets you add a bottom border and adjust its color to your primary header.
Border Box Shadow
You can enable or disable bottom border box shadow of your primary header.
This option lets you adjust the spacing below your primary header. By default this option is set to 0 but if you would like to have a space between your primary header and the content then you can adjust the settings to like liking.