Adding a custom field to Export Order Items?

Hi

I would like to re-arrange the order of the default Export Order Items Options list.

I would like to uncheck Item Meta and add it as a custom field so it appears last. (At the moment, it throws the data into multiple columns in the CSV export messing up the column order).

https://snag.gy/7gGHec.jpg

What do I choose for the Type (is “Order Meta” correct?) and Value (meta key?) to add the Item Meta?

Many thanks!