Dividends do not have a gain or loss. Did you have sales in a investment account? You get a 1099B for those. Did you get a consolidated statement? That will have sections for 1099-Int and 1099-Div and 1099B. You need to enter each section in the right place. So read it carefully and look for headings.... 1099-INT for interest or 1099-DIV for Dividends or 1099B for sales.
Enter a 1099B under
Federal Taxes Tab
Wages & Income
Then scroll down to Investment Income,
Then Stocks, Mutual Funds, Bonds, Other - click Start or Update
But you do not report dividends, interest, buys or sells in IRA or 401K or retirement accounts. You only report distributions and 1099R forms.