how to add investment loss where no 1099 form, need form 8949 and schedule D

In order to populate the Schedule D and related 8949, you will enter the details related to the loss on the investment income section of TurboTax.

To accomplish this, here is how to enter the information in TurboTax Online:

• Navigate to Federal > Wages & Income > Investments and Savings (1099-B, 1099-INT, 1099-DIV, 1099-K, Crypto) > Add/Edit
• Choose Add Investments, then Enter a different way
• Choose "Other" as the investment type and continue
• Choose a description 
• It will ask "What type of investment did you sell?", answer according to what type of investment this was
• Complete the rest of the information requested in the interview