Amend

You filed without entering any information for the child tax credit?   Did you claim a dependent child on your 2021 return?   Look at line 28 of your Form 1040.   Do you see an amount there?   If you entered a qualfiying child then the software automatically puts the CTC on that line.  Later when you go through Federal Review you are supposed to answer questions to reconcile the amount of advance payments received with the amount the software entered already.  So you might be okay.

If you messed it up, the IRS will likely find your mistake and correct it, but it will delay your refund.

PREVIEW 1040

https://ttlc.intuit.com/questions/1901539-how-do-i-preview-my-turbotax-online-return-before-filing

Click on Tax Tools on the left side of the screen. Click on Tools. Click on View Tax Summary. Click on Preview my 1040 on the left side of the screen.

It is possible, but I wouldn't count on it. You would be better off amending. Be sure that you have all your documents so that you don't have to do this more than once. Also, you will have to wait until your return has been accepted by the IRS.

The function is not yet available for 2021, but the steps will be below.

1. Sign in to TurboTax
2. Scroll down to Your tax returns and documents, select 2020, then Amend (change) your return
   • If you only see the option to amend 2020 or earlier, it's because you can't amend an unfiled 2021 return. Instead, select Pick up where you left off so you can make any changes before you file
3. Carefully follow the instructions to amend1

@Chi2006 

I think Coleen and I interpreted your question differently.

We need clarification on what you were asking about. 

 When you say you did not get the CTC "last year" were you referring to those monthly payments that were issued between July and December---the "advance" CTC payments?

Or do you mean you did not get the child tax credit on your 2020 tax return?   Please look at your 2020 tax return on line 19 to see if you received the CTC on that tax return.

I opted out the monthly payments is what I’m saying 

I was thinking CTC should me more because I opted out of the monthly payments 

Yes I got accepted already 

Do you know the amount for the CTC mine says 3,000 I thought it was more this year

 The amount of credit actually increased for 2021 (up to $3,600 for children under 6, and up to $3,000 for those between 6 and 17).

Would I get an additional credit  for opting out the monthly payments ??

No, the maximum credit is as stated by @ColeenD3 and placed here again for your convenience. There is no additional credit for opting out of the monthly payments.

• The amount of credit actually increased for 2021 (up to $3,600 for children under 6, and up to $3,000 for those between 6 and 17)

If your child is older than 6 you got the max amount.  If you had gotten the monthly payments the the 3,000 would be reduced.