A us citizen living aboard, trade stocks in a foreign brokerage company and have capital gain, where and how to report the capital gain?

[TomYoung]

In the "online" products "Premier" or above is needed to record security sales.  In the "desktop" products all of them are capable of processing simple security sales.

You use the "Stocks, Mutual Funds, Bonds, Other" interview and tell TurboTax that no 1099-B was received.  Proceeds and cost basis are translated to US dollars using the spot rate in effect on the appropriate date.

https://fiscal.treasury.gov/reports-statements/treasury-reporting-rates-exchange/

Tom Young