That is capital gain/ loss .
You enter this just as if the property disposed was in the USA --- Tell TurboTax that you have assets that were disposed in 2018. All your basis, sales proceeds etc. must be converted to US$ of the day -- the exchange rate being based on US Treasury, known sites, or bank in the country where the transaction took place. Any taxes paid on this gain/loss situation to a foreign taxing authority is eligible for foreign tax credit or deduction ( if use itemized deduction )
If you need more on this , please include your questions in comments and I will circle back
