Add logo to beginning of menu
<?php
//* Do NOT include the opening php tag shown above. Copy the code shown below.
// Notes:
// Add logo via css background imgae.
// Refrance:
//* https://developer.wordpress.org/reference/functions/wp_nav_menu/
//* Filter menu "primary" to add logo structure
add_filter( 'wp_nav_menu', 'pb_menu_logo', 10, 2 );
function pb_menu_logo( $menu, $args ) {
$args = (array)$args;
if ( 'primary' !== $args['theme_location'] )
return $menu;
$logo = '<div class="menu-logo"></div>';
return $logo . $menu;
}