Hello,
There are 2 headers on your site, so header for the Home page should be edited separately here – https://prnt.sc/21lDeJpMAT1q
“But now I want to make the menu transparent without the white band. The background must be the entire image of the slide. How do I do it?” – enable header overlap (Theme Options > Header builder (by default header for all pages are edited, but if you want to edit Home page header – click on Multiple headers, as was mentioned) > Header overlap & transparent > Header overlap > On, then go to Top header – https://prnt.sc/IthoGW4XLynM > WCAG Background Control > set transparent https://prnt.sc/zGGHyUjbI_Lj > Publish changes. Check the result on site after closing the editor, maybe you will need to clear the cache of your browser.
Regards