You already e-filed? Did you go through the child tax credit section and enter anything? You were supposed to answer questions about whether you received any of the advance payments. Did you claim your child in My Info? Do you see anything on line 28 of your Form 1040?
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.