Line 2 is any carry forward basis from prior years which comes form line 14 on the last filed 8606.
Note: that if you had a contribution and a distribution in the same year then TurboTax does not use the 8606 lines 6-15, it will use the "Taxable IRA Distribution Worksheet" from IRS Pub 590B Worksheet 1-1 as indicated by an * (asterisk) next to line 15 on the 8606. Using that worksheet can be a tax advantage.
https://www.irs.gov/publications/p590b#en_US_2019_publink1000230851
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
