Transaction List Columns Subtab
The Transaction List Columns subtab lets you configure how transaction column fields appear in the My Account area of your site. When you enable column management for a list, you can specify what fields appear.
You can configure the following transaction lists:
- Order History
- Quotes
- Returns
- Open Invoices
- Paid Invoices
To add new column for the above transactions page
Enable the column management option according to the requirement:

Here we are going to add a new column for PO number in the order history page

then save the configuration , it will be get show in the order history page
