the first section is the sticky bar (always display) currently hidden because no link 
  — to display the top right menu, click on it, go to advanced settings, scroll down, choose responsive and uncheck hide on desktop hide on mobile, hide on tablet

the second section is empty (height 0), and has a margin to simulate the sticky bar, always needs to be displayed

the third is the menu (display on computer, never on tablet and mobile) currently hidden because no link 

the fourth contains the necessary css for the menus, do not delete, never display

/!\  to display a hidden section, select the section, go to advanced, scroll down and click on responsive then uncheck hide on destkop hide on tablet hide on mobile

Attention, the second menu may appear with a gap when previewing, but if you disconnect and consult the site the gap is not there

if one of the menus has been deleted by mistake, it is possible to import them with template, in page it is named easy-to-modify-header . It is also possible to import indiviually with template, but the menu will not work without the code block 

How to access navigator :