You can import most  1099 info.  Capital Gains are on 1099 Div and 1099 B and maybe 1099 Int.   What are your Capital Gains from?  If you have sales you enter the Sales price and cost and then Turbo Tax calculates the Gain or Loss.  

Importing 1098 &1099 forms to Online version
https://ttlc.intuit.com/community/entering-importing/help/how-do-i-import-my-1099/00/26254

Thanks, I didn’t realize that capital gains were included in the 1099 imports.