It depends on whether you are the custodial* or non-custodial parent. If you are the non-custodial parent, you do not enter the child at all. There's nothing to claim.
The custodial parent should still enter the child, in TurboTax, as you can still claim EIC, day care credit and Head of Household even though the non-custodial parent is claiming the dependent, child tax credit and rebate credit**.
*For tax purposes, there is no such thing as joint custody, regardless of what your legal agreement says. The requirement, to be custodial parent, is that the child live with you MORE than 50% of the time. One of you has to be the custodial parent and the other the non-custodial parent.
**Whoever claims the child, on the 2020 return, gets the $1100 child stimulus (500+600), even if the other parent already received the same amount.
