Logo centered and menu below logo

@zheenorewp,

Add CSS in below class in your custom style sheet or CSS from the editor.

.show-alt-nav .site-header {
   flex-direction: column;
}

Also, apply 50px padding instead of 80px in “.site-header” class as below

.wp-custom-logo .site-header {
  padding: 50px 0;
}

Apply width in custom-logo

.site-header .custom-logo {
  width: 200px; /* width according to your requirments */
}

Hope this will get your desired result

omg, yes thank you! ??

@addweb-solution-pvt-ltd

omg, yes thank you! ??

@zheenorewp, if your issue is resolved. please update the ticket.