add a column to the Event Espresso 4 Registrations CSV report that displays the total tax amount for the transaction

csv_transaction.php

<?php
//* Please do NOT include the opening php tag, except of course if you're starting with a blank file

add_filter( 'FHEE__EE_Export__report_registrations__reg_csv_array', 'espresso_add_total_taxes_column', 10, 2);
function espresso_add_total_taxes_column( $reg_csv_array, $reg_row ) {
    $registration = EEM_Registration::instance()->get_one_by_ID( $reg_row['Registration.REG_ID'] );
    $sub_line_item_details = array();
    if( $registration instanceof EE_Registration && $registration->is_primary_registrant() ) {
        $sub_line_items = EEM_Line_Item::instance()->get_all(
          array(
            array(
                'TXN_ID' => $reg_row['TransactionTable.TXN_ID'],
                'LIN_type' => EEM_Line_Item::type_tax_sub_total
            ),
            'order_by' => array( 'LIN_order' => 'asc' )
          )
        );
        foreach( $sub_line_items as $sub_line_item ) {
            $sub_line_item_details[] = sprintf( '$%s', $sub_line_item->get_pretty( 'LIN_total', 'localized_float' ) );
        }
    }
    $reg_csv_array[ __( 'Total Taxes', 'event_espresso' ) ] = implode('+', $sub_line_item_details );
    return $reg_csv_array;
}