I am trying to claim a dependent who does not have SSN or TIN no. How can I claim her?

[Anonymous]

you can't.  

if as the prospective adoptive parent you don't have and are unable to obtain the child's social security number (SSN), you should request an adoption taxpayer identification number (ATIN) or individual taxpayer identification number (ITIN).

An ATIN is available if a child who is a U.S. citizen or resident is lawfully placed in your household for legal adoption. To obtain an ATIN, use Form W-7A, Application for Taxpayer Identification Number for Pending U.S. Adoptions. For more information, refer to the Instructions for Form W-7A (PDF) and to Adoption Taxpayer Identification Number.
If the child isn't a U.S. citizen or resident, and if the child qualifies as a dependent, a TIN is still required. To obtain an ITIN, use Form W-7, Application for IRS Individual Taxpayer Identification Number. For more information, refer to Individual Taxpayer Identification Number (ITIN).
Please note that for tax years 2018 through 2025, you can't claim the child tax credit on either your original or an amended return if your child doesn't have an SSN valid for employment by the due date of your return (including extensions). If your child has an ATIN or an ITIN, your child may qualify you for the credit for other dependent

[Opus 17]

You can't.

If the child is eligible for an SSN, apply for it now.  Wait for it to come before filing a tax return.  You should also submit an automatic extension request to extend your filing deadline to October 15.  There are significant tax benefits for a dependent that are only paid if you file an on-time tax return with an SSN.  (For 2020, on-time means filed before July 15, or filed before October 15 if you got the extension before July 15.)

If the child is not eligible for an SSN, you need to apply for an ITIN, international tax ID number.  This is done with form W-7.  Start by using a fake ITIN to prepare your return, try using 999-88-9999.  You can't e-file.  Print the return and use white-out to cover the fake SSN.  Prepare the W-7 application for the dependent and attach any proof required by the instructions.  Mail the W-7, the proof, and the tax return, to the IRS address for the ITIN application.  Use a mail service with tracking and proof of delivery.  After the IRS assigns an ITIN, they will process the tax return.