You need SSNs. 

In order for all of the applicable credits to apply you must have either an SSN, or ITIN. Without them, No Child Tax Credit, Child Care Credit, Earned Income Credit.  Must be the SSN/ITIN assigned to the child. No workarounds, and if filed by paper return will be rejected. 

Since I see on the irs website that you are both accurate:  Publication 972 (2020), Child Tax Credit and Credit for Other Dependents | Internal Revenue Service ...

Then ProSeries should update this worksheet:  Child Tax Credit and Credit for Other Dependents Worksheet
Part 1, line 2 Number of other dependents, including qualifying children without required social security number:___ x $500

Thanks Lisa but as I posted below ProSeries should update this online Worksheet is it's incorrect:

Child Tax Credit and Credit for Other Dependents Worksheet
Part 1, line 2 Number of other dependents, including qualifying children without required social security number:___ x $500

~ Liz