You can enter summaries. There are two ways to show the summary entries on the tax return. One way allows adjustments and the other way doesn't. TurboTax automatically chooses the correct way, but the TurboTax screens don't make a clear distinction between the two ways of reporting it.
Enter the summary in TurboTax exactly as you showed in your screen shot. Check the adjustments box and enter the total adjustments and the code(s). When you enter a summary with adjustments, you must attach a statement to your tax return showing the details of each transaction. The attached statement can be a photocopy of the pages of the 1099-B from your broker that list the individual sales. Since e-filing has ended for 2018, you have to be filing your tax return by mail, so just attach the required pages at the back of the mailed return.
