I owe almost 100 dollars and I can't figure out why. The form sent to me says that I violated Penalty Code B, but nowhere on TurboTax said I still had taxes owed or that I paid late.
Did you look at your state return before you filed it? Did it show that you owed tax to your state? Or did the state change something or disallow some sort of credit, etc. after they processed your return? TurboTax does not receive any information from the state after you file, so no one at TT knows why you owe something now.
If you owed tax due and did not pay it by the deadline, that would explain why you owe a penalty or interest now.
You must pay your state tax due using the state’s preferred method of receiving payment. For most states that will be by making a payment to the state’s own tax website, or by mailing a check or money order.
https://ttlc.intuit.com/questions/1901670-how-do-i-contact-my-state-department-of-revenue
TurboTax has a special phone number for help with IRS/state tax letters, which will be easier than going through regular Customer Support. At the page below, click on the blue button that says "Get Help from TurboTax Support". Then it will ask you what tax year is your letter. Then it will ask you what the letter concerns. Then it will show you the phone number during posted business hours.
https://support.turbotax.intuit.com/irs-notice/audit-support/