Interest is reported on a Form 1099-INT in the TurboTax program even if you did not actually receive a 1099-INT.
Enter the payer's name in the section for Received from and the amount of interest received in Box 1. Interest is reported in US dollars only.
If asked for a EIN for the payer and the payer does not have an EIN just enter any 9 digit number.
Online returns -
Enter interest income in the Search box locate in the upper right of the program screen. Click on Jump to interest income
On the screen Did you receive any interest income? Click on Yes
On the next screen click on Continue
On the screen Let's import your tax info Click on Change how I enter my form
On the screen How do you want to add your 1099‑INT? Click on Type it in myself