How get the logo for my custom theme

Setting up theme logo with custom size in functions.php :

function theme_prefix_setup() {

    add_theme_support( 'custom-logo', array(
        'height'      => 100,
        'width'       => 400,
        'flex-width' => true,
    ) 
);

}
add_action( 'after_setup_theme', 'theme_prefix_setup' );

Output custom logo:

function theme_prefix_the_custom_logo() {

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

}