the rules that a child must be have a SSN under IRC §§24(e)(1) and 32(c)(3(D)(i) are not absolute. the IRS has issued guidance for a child who was born and died in the same year and does not have a SSN for the purposes of being claimed as a dependent, earned income tax credit, and Child Tax Credit (ACTC)

https://www.irs.gov/faqs/earned-income-tax-credit/qualifying-child-rules/qualifying-child-rules-1

"1. The Earned Income Credit

Generally, a child must live with you in the United States for more than half of the tax year to be a qualifying child. You may treat a child who was born alive or died in 2019 as having lived with you for more than half of 2019 if your main home was the child’s main home (or would have been) for more than half of the time he or she was alive in 2019.

The earned income credit requires that you provide a valid social security number (SSN) for your qualifying child. If you meet all of the other requirements to claim this credit, and your child was born and died in 2019 and didn't have an SSN, instead of an SSN, you may enter "DIED" on line 2 of Schedule EIC (Form 1040 or 1040-SR), Earned Income Credit and attach a copy of the child's birth certificate or a hospital medical record showing a live birth. 

   2. Dependency and/or Child Tax Credit  

Generally, the child must live with you for more than half of the tax year to be a qualifying child. You may treat a child who was born alive or died in 2019 as having lived with you for more than half of 2019 if your main home was (or would have been) the child's main home for more than half of the time he or she was alive in 2019. Whether your child was born alive depends on state law.

If you meet all of the other requirements to claim the child as a dependent, you usually must provide a taxpayer identifying number (TIN) for the child. If your child was born and died in 2019 and didn't have an SSN or other TIN, instead of a TIN, you may enter "DIED" in column 2 of the Form 1040, U.S. Individual Income Tax Return or Form 1040-SR, U.S. Tax Return for Seniors (PDF) and attach a copy of the child's birth certificate or a hospital record showing a live birth.

The child tax credit requires that you provide a valid SSN for your qualifying child. If you meet all of the other requirements to claim this credit and your child was born and died in 2019 and didn’t have an SSN, instead of an SSN, you may enter “DIED” on column 2 of the Form 1040 or Form 1040-SR and attach a copy of the child’s birth certificate or a hospital record showing a live birth."

However, without a valid TIN, the return will need to be paper-filed.