The turbo tax software did not pick up all the Federal Income Tax withheld in processing my return. How do I correct this ? the return has been registered but not filed.

From what?  W2 box 2 and 1099R box 4 or 1099G?

If you haven't efiled or mailed your return or it rejected you can go back in and change anything you want.  Do not click on Amend!

Click on Add a State to let you back into your return.

From Tax Home (the first screen you see after you sign in), scroll down to Your tax returns & documents. You may have to select Show to open the drop down.

Select 2021, and then select Add a State (you're not actually adding a state, this is just the workaround).

Then Edit the form you need to add the withholding.

In addition to checking or changing your forms that include withholding amounts as suggested by Champ VolvoGirl, did you also make estimated payments that were not included in your return?

If so, use these steps to enter your estimated payments:

• On the top row of the TurboTax online screen, click on Search (or for CD/downloaded TurboTax locate the search box in the upper right corner)
• This opens a box where you can type in “estimated tax payments” (be sure to enter exactly as shown here) and click the magnifying glass (or for CD/downloaded TurboTax, click Find)
• The search results will give you an option to “Jump to estimated tax payments”
• Click on the blue “Jump to estimated tax payments” link

@rey87nold