create payment optins fragments

add_filter('woocommerce_gateway_icon', 'custom_override_gateway_icon', 10, 2);
function custom_override_gateway_icon($icon_html, $gateway_id) {
    if($gateway_id == 'bacs') {
        $icon_html = '<img src="http://yoursite.com/wp-content/uploads/2017/05/bank-transfer.png">';
    }
    return $icon_html;
}