1.  Login to your SureDone account.

2. On the navigation bar, click SETTINGS>ORDERS & SHIPPING>Picklist & Invoice

3. Click on the (+) sign to expand Picklist & Invoice options

4. Scroll down and select the custom fields you want to use under "Invoice Fields Set".  To select more than one, hold down the control key (or command key on a Mac)

5. Press Save Settings

Similarly, if you want to DELETE any custom fields from your picklist - you can select and highlight that field from "Invoice Fields Set" and check "Remove". Then click on "Save Settings".