add_theme_support( 'custom-logo' ); logo option backend nog showing code example
Example: sile logo wordpress programmatically
$custom_logo_id = get_theme_mod( 'custom_logo' );
$logo = wp_get_attachment_image_src( $custom_logo_id , 'full' );
if ( has_custom_logo() ) {
echo '<img src="' . esc_url( $logo[0] ) . '" alt="' . get_bloginfo( 'name' ) . '">';
} else {
echo '<h1>'. get_bloginfo( 'name' ) .'</h1>';
}