Have you entered their Social Security numbers? How old are your children? You only get the CTC for children who were younger than 17 at the end of 2020---so if any of them are over 16 you cannot get CTC for them. If you have a child who was born in 2020 make sure you say the child lived with you the whole year
Look at your 2020 Form 1040 to see the child-related credits you received
Child Tax Credit line 19
Credit for Other Dependents line 19
Earned Income Credit line 27
Additional Child Tax Credit line 28
Child and Dependent Care Credit line 31 (from line 13 of Schedule 3)
The additional child tax credit (ACTC) is not a separate credit from the child tax credit (CTC). It is a refundable amount you get if your tax liability was so low that you did not get the full $2000 (per child) CTC. That is, part of the CTC may be on line 28 of form 1040 (2020 version) instead of line 19 (lines 18b and 13a in 2019). The ACTC is calculated on form 8812 and is basically 15% of your earned income over $2500. The ACTC is a maximum of $1400 per child (not $2000). At $70-90K, you, most likely already got the full $2000 per child.
"First time doing MY own taxes. Looking into the requirements for the Additional Child Tax Credit and it seems like WE would receive it". Does "WE" mean your filing Married filing jointly or just mean you and your kids.