Insert custom field into status e-mail

-- HikaShop version -- : 3.2.1
-- Joomla version -- : 3.7.5

I have created a custom field with the column name "order_tracking_number" in the "order" table, so that I can add the tracking number for each shipment out. I would like to add this field to the status e-mail that goes out when I change the order status to "shipped", so that it include the order tracking number from that order.
How do I insert a custom field from the order table into the status e-mail about an order? I know I need to edit the "Order notification" e-mail, but I can't figure out the text that needs to go in to call the "order_tracking_number" field.
THese don't seem to work:
{LINEVAR:ORDER_TRACKING_NUMBER}
{VAR:ORDER_TRACKING_NUMBER}
{TXT:ORDER_TRACKING_NUMBER}

Hello,

The solution will just be to directly use options of the "DISPLAY : MAIL" tab of your order custom field configuration page via "Hikashop->Display->Custom fields".