how to enter treasury T Bill and I saving bond 1099?

You can enter the total in Box 3 but you must ensure that every item on each 1099 is exact like EIN etc.,

Form 1099-INT reports interest from banks, brokerages, and other financial institutions. Here's how to enter a 1099-INT:

1. Sign in to your TurboTax account and open or continue your return.
2. Select Federal from the menu, then Wages & Income.
3. Locate the section titled Investments & Savings and select Show More, then select Start or Revisit next to Interest on 1099-INT.
4. Select Yes on the screen Did you receive any investment income? then Continue.
   • If you see the screen Your investments & savings or Here's your 1099-INT info, select Add investments or Add another 1099-INT, then Continue.
5. On the next screen, select how you want to enter your Form 1099-INT:
   • If you want to import your form, search for your brokerage or financial institution. Sign in to your online account and select Get my form.
   • If you want to upload a copy of your form or manually enter the info, select Enter a different way, and follow the instructions to enter your 1099-INT.
6. On the screen Do any of these uncommon situations apply? check the boxes according to your situation and Continue.