Hi there!

Thanks for reaching out to us.

Please use the following code in your custom CSS:

@media (max-width: 575px){
#sp-header .sp-module {
    display: block;
}
#sp-menu .sp-megamenu-wrapper {
    order: 1;
}
}

Here is all about custom code placement in Helix Ultimate: https://www.joomshaper.com/documentation/helix-framework/custom-code-css-js-meta

Best Regards