If by "transactions" you are referring to the buying and selling of cryptocurrency, then any conversion of one cryptocurrency into another or into US Dollars constitutes a "sale", a sale that needs to be reported using the "Stocks, Mutual Funds, Bonds, Other" interview, telling TurboTax that no 1099-B was received. A conversion into another cryptocurrency requires that you convert the cryptocurrency received into US Dollars at the spot price and report that as the proceeds.
You can select "Everything else" as the type of investment sold and after that you simply enter the proceeds of the sale, sale date, cost of the coin sold, and date of acquisition.
Tom Young
