WP Customizer Footer Logo #wp

customizer.php

// Add first

$wp_customize->get_setting( 'logo_icon' )->transport = 'postMessage';

// Add 2nd

/**
	 * Add a control to upload the Footer Logo.
	 * Add a setting for the site Footer Logo.
	 */
	$wp_customize->add_control(
		new WP_Customize_Image_Control(
			$wp_customize,
			'logo_icon',
			array(
				'label'    => __( 'Footer Logo', 'quantum' ),
				'section'  => 'title_tagline',
				'settings' => 'logo_icon',
				'priority' => 8,
			)
		)
	);

// Add to $wp_customize
$wp_customize->selective_refresh->add_partial(
	'logo_icon',
	array(
		'selector'        => '.ftr-logo',
		'render_callback' => 'quantum_customize_partial_footer_logo',
	)
);

// Add function and customize if needed
/**
 * Render the footer logo for the selective refresh partial
 */
function quantum_customize_partial_footer_logo() {
	$custom_icon = get_theme_mod( 'logo_icon' );
	if ( $custom_icon ) {
		$icon_id = attachment_url_to_postid( $custom_icon );
		$logo    = wp_get_attachment_image( $icon_id, 'full' ); ?>

		<div class="ftr-logo">
			<a rel="noopener noreferrer" href="<?php echo esc_url( home_url( '/' ) ); ?>">
				<?php
				echo wp_kses(
					$logo,
					[
						'img' =>
						[
							'src'    => true,
							'srcset' => true,
							'sizes'  => true,
							'class'  => true,
							'id'     => true,
							'width'  => true,
							'height' => true,
							'alt'    => true,
							'align'  => true,
						],
					]
				);
				?>
			</a>
		</div>

		<?php
	}
}
              
// Call function
<?php quantum_customize_partial_footer_logo(); ?>