1) Read the letter, which likely explains Why you owe, and for which Year. For IRS guidance on understanding, see https://www.irs.gov/individuals/understanding-your-irs-notice-or-letter
2) Post back here with your findings, and someone in this forum may have further ideas.
3) To contact TT Live Support (one-on-one help, which you’re apparently paying for) :
https://ttlc.intuit.com/community/expert-review/help/how-do-i-connect-with-a-tax-expert-in-turbotax-...
