try something like this in your functions.php
add_filter( 'wppizza_filter_orderhistory_order_info', 'my_orderinfo_add_total', 10, 4 );
function my_orderinfo_add_total($markup, $order_id, $customer_details, $order_details){
/** add total after $markup['last_update'] **/
$markup['last_update'] .='<div>'.__('Total').': '.wppizza_output_format_price($order_details['total']).'</div>';
return $markup;
}