Deductions & credits

You can enter the interest as if it were on Form 1099-INT, but it needn't be. 

You don't need the IRS EIN.

Enter under

Wages & Income

Interest and Dividends

Interest on 1099-INT   

Select "Add investments" if needed

Select "Skip Import" if needed

Select Interest 1099-INT 

Enter "IRS" as the Payer and the amount