I am separated in a 50/50 shared custody with a significant gap in incomes. Can either of us claim line 214 child care deduction or must it be lower income earner?

We will likely be splitting actual payments  80% // 20% though I am not thrilled with Ex's justification for need of childcare.  I was set to be juggle my schedule to not need any childcare and thus create significant savings.  Ex was not able to do the same.