How do I get the Child Tax Cred for my oldest? The issue: I received the cred for my other kids but not her. I couldn't claim her last year, ex's year. Claiming her 2021

My ex and I alternate years in which we claim our daughter on taxes. He claimed her last year, so I did not receive the child tax credit for her, even though she's with me 85% of the time or more.  What complicates it is that I have other children with my husband for which I already received the credits. Is there a form I can file to get the credit for just one dependant? TIA