You have to verify your identity with the IRS.
Go to this IRS website for a CP5071 notice - https://www.irs.gov/individuals/understanding-your-cp5071-cp5071c-or-cp5071f-notice
For IRS letter 5071 Verification, See these 2 links……
https://turbotax.intuit.com/tax-tips/security/tips-for-handling-identity-verification-requests-from-the-irs/L55RhaS2B
IRS https://www.irs.gov/identity-theft-fraud-scams/identity-and-tax-return-verification-service
TurboTax does not verify your identity for you. This is between you and the IRS.
I HAVE TO VERIFY MY IDENTITY
Sometimes the IRS chooses returns randomly to request verification of identity and sometimes there is something on the return that triggers the request. No matter why the IRS has required you to verify your identity, you need to follow their instructions in order to receive your refund. If you do not verify your identity you will not get your refund.
https://www.irs.gov/identity-theft-fraud-scams/identity-verification-for-irs-letter-recipients