How do I remove foreign tax credit I don't have?

This means you have a 1099-DIV or 1099-INT with an amount in the "Foreign Taxes Paid tax (Box 6). 

(In the 1099-DIV or 1099-INT interview screen, you may have to check the box "My form has info in more than just these boxes" to see if there is a Box 6 entry).

If you don't want to upgrade and don't mind losing the tax credit, you can try to "Edit" Box 6 and remove the entry.

If that doesn't work, you will have to delete the Form 1099-DIV or 1099-INT.

See: How do I delete forms in TurboTax Online?

After deleting the 1099-DIV or 1099-INT, log out of the program. When you log back in, use the Delete a Form tool to confirm the 1099-DIV or 1099-INT has been removed from the list of forms in your return. If gone, you can re-enter the form without the Box 6 amount.