добавляем логотип в customizer WordPress

function.php

function theme_prefix_setup() {
    add_theme_support( 'custom-logo' );
}
add_action( 'after_setup_theme', 'theme_prefix_setup' );

// или

function theme_prefix_setup() {
    add_theme_support( 'custom-logo', array(
        'height'      => 175,
        'width'       => 400,
        'flex-width' => true,
    ) );
}
add_action( 'after_setup_theme', 'theme_prefix_setup' );

// Варианты с хидер текстом

add_theme_support( 'custom-logo', array(
    'header-text' => array( 'site-title', 'site-description' ),
) );

// Получение
// Returns markup for a custom logo.
get_custom_logo( $blog_id = 0 )

// Displays markup for a custom logo.
 the_custom_logo( $blog_id = 0 )

// Returns a boolean true/false, whether a custom logo is set or not.
has_custom_logo( $blog_id = 0 )

function twentysixteen_the_custom_logo()
{
    if ( function_exists( 'the_custom_logo' ) )
    {
        the_custom_logo();
    }
}


/*
height
(int) Expected logo height in pixels.
Themes can use built-in image sizes (like thumbnail) or register a custom image size and use that.

width
(int) Expected logo width in pixels.

flex-height
(boolean) Whether to allow for a flexible height.
Showing the logo in a vertical sidebar (like Twenty Fifteen) is a good example for when a flexible height can make sense.

flex-width
(boolean) Whether to allow for a flexible width.
If a theme has room horizontally, flex-width gives users more freedom in how their logo can be displayed.
*/