can I get the total on 8949 to appear on Sched D line 1b

To report the transaction on line 1b, you must select Box A on IRS form 8949 Sales and Other Dispositions of Capital Assets.  Then select I need to adjust my total cost basis  and select code B.

You may enter the summary information instead of each individual transaction.  Create a .PDF of the IRS form 8949 to upload into TurboTax Online.  Follow these steps.       

1. Down the left side of the screen, click Federal.
2. Down the left side of the screen, click Wages & Income.
3. Click the down arrow to the right of Investments and Savings.
4. Click to the right of Stocks, Cryptocurrency, Mutual Funds, Bonds, Other (1099-B).
5. Click Add investments.
6. On the Let's import your tax info screen, select Enter a different way.
7. On the OK, let's start with one investment type screen, select Stocks, Bonds, Mutual Funds, then Continue.
8. At the screen Which bank or brokerage, enter the information.  Click Continue.
9. Do these sales include any employee stock, enter No.
10. Do you have more than three sales, enter Yes.
11. Do these sales include any other types of investments, enter No.
12. Did you buy every investment listed, enter Yes.  Continue.
13. On the screen Now, choose how to enter your sales, select Sales section totals.  Select Continue.
14. At the screen Look for your sales on your 1099-B, select Continue.
15. You will now be able to enter the total proceeds (sales) and cost basis.  Select Short term basis reported to IRS (covered) as the sales section category.
16. When finished, select Continue.
17. You can add additional sales totals by selecting the Add another sales total on the Review your sales section totals screen.
18. When completed, close the record and click Continue.
19.  At the screen Now, we'll help you upload your 1099-B since the IRS requires a copy, browse and select your document.  Select Continue.
20. When you upload your document, your filing instructions will not show that anything needs to be mailed in, and no IRS form 8453 will be generated.

is this due to adjustments for wash sales, AMD etc?  it depends how many sales you have.

if it's not many you are better off entering those items as a 1099 with "one by one" and provide the details which will go on Form 8949 and Sched D Line 1b (or wherever it belongs).  You can split up the 1099 and enter anything that doesn't have an adjustment as a separate 1099B in TT using "sales summary" input but without any adjustment (No Form 8949, goes on Sched D Line 1a).  This avoids mailing the 1099B details to the IRS.

If you have a lot of these items you can enter as a sales summary with adjustments and mail the details to the IRS.

When you make adjustment to a sales summary it will reflect on Form 8949 without the details and a description "see attached statement" and you will need to mail Form 8453 with the details usually in the form of the 1099B.

Generally TT encourages the adjustment of sales summaries and mailing of Form 8453 which can be avoided in a lot of cases.