coupon on orders page

Hi,

I want to show the coupon code which is used by user on the orders page, I created two columns look at the image https://ibb.co/hDcy5ks, one is working and other one which is “coupon code” is not working, what is the short-code for the coupon which is used by the user. I tried so many [coupon_code], [coupon_description], and [coupon_discount]. but non of them are working.

and I used this code in the function.php for creating a columns

// ADDING 2 NEW COLUMNS WITH THEIR TITLES (keeping “Total” and “Actions” columns at the end)
add_filter( ‘manage_edit-shop_order_columns’, ‘custom_shop_order_column’, 20 );
function custom_shop_order_column($columns)
{
$reordered_columns = array();

// Inserting columns to a specific location
foreach( $columns as $key => $column){
$reordered_columns[$key] = $column;
if( $key == ‘order_status’ ){
// Inserting after “Status” column
$reordered_columns[‘howdidyouhearaboutus’] = __( ‘How did you hear about us?’,’theme_domain’);
$reordered_columns[‘coupon_show’] = __( ‘Coupon Code’,’theme_domain’);

}
}
return $reordered_columns;
}

// Adding custom fields meta data for each new column (example)
add_action( ‘manage_shop_order_posts_custom_column’ , ‘custom_orders_list_column_content’, 20, 2 );
function custom_orders_list_column_content( $column, $post_id )
{
switch ( $column )
{
case ‘howdidyouhearaboutus’ :
// Get custom post meta data
$my_var_one = get_post_meta( $post_id, ‘howdidyouhearaboutus’, true );
if(!empty($my_var_one))
echo $my_var_one;

// Testing (to be removed) – Empty value case
else
echo ‘<small>(no value)</small>’;

break;

case ‘coupon_show’ :
// Get custom post meta data
$my_var_two = get_post_meta( $post_id, ‘coupon_show’, true );
if(!empty($my_var_two))
echo $my_var_two;

// Testing (to be removed) – Empty value case
else
echo ‘<small>(no value)</small>’;

break;

}
}