When you dropship an order, each purchase order line keeps the customization from the order line, such as engraving text or a personalization. Your supplier can then see what to make or engrave without checking the order.
Which purchase orders carry the customization
Dropship purchase orders created from an order, whether SKULabs creates them automatically or you create them in the order's Dropships and purchase orders panel. The customization is the same line metadata you see under the item on the order. See How to import line item customizations into SKULabs from my sales channel?
Dropship purchase orders also use the order's currency (or the store's, then the account's), so the PO total shows in the right currency.
How to show the customization on the purchase order
Standard purchase order template: edit your store's purchase order template, open Toggle advanced options, and turn on Show metadata column. The column is hidden by default, so existing purchase orders don't change until you turn it on. This template is also the one used for the purchase order e-mail sent to the supplier for automatic dropships.
New (Liquid) purchase order templates: each line has item.metadata, a list of name and value pairs. To print the values:
{% if item.metadata and item.metadata.size > 0 %}{{ item.metadata | map: 'value' | join: ', ' }}{% endif %}
For more on dropshipping, see Managing dropshipping in SKULabs.