TurboTax does not support deferring capital gain by investing in Qualified Opportunity Funds, and it does not support Form 8997. There is no way to enter the investment. If you want to defer capital gain by investing in a Qualified Opportunity Fund, you cannot use TurboTax to file your tax return.

The form that is used to report your investment in a Qualified Opportunity Fund is Form 8997. Form 8996 is filed by the fund, not by the individual investors.

Is it posible to enter the appropriate deferral information regarding QOZ investment on Form  8949 using Override Function. then complete Form 8997 manually (outside of TurboTax), then print entire TurboTax filing, insert Form 8997 and file a paper copy with IRS. Does that work?

Yes you can do that ... be aware that making entries in the FORMS mode will void the accuracy guarantee and overrides will keep you from efiling.