Bad private debt

Hi all, how do I enter bad private debt for the tax return 2020? I have seen several online discussions, but none works for my desktop Turbo Tax 2020. In detail, I have entered already one 1099-B from a bank under Investment Income. When I try to update the Investment Income, it only allows for "more sales", and does not give my another option, i.e. bad debt.

Thx