Hello,

You might have the custom fields set to internal only.  If you do, make sure to place a check mark in the Public boxes.

(picture below)

Gear Icon > Account and Settings > Sales > Sales Form Content

where is this in desktop?

There’s an easy way to do this in QuickBooks Desktop, xcollett.

It’s a great idea to add a custom field and include it upon printing the sales form. I’ll show you how:

1. From the Lists menu, select Templates.
2. Double-click the template.
3. Click Additional Customization.
4. Go to the tab where you enter the custom field.
5. Tick (✓) the Print column.
6. Click OK, then OK.

There you have it. Feel free to post again if there's anything that I can help you with.