You do need to enter your expenses in the Dependent Care Credit section, regardless of the flexible spending account. If you skip this section, and do not properly enter your dependent care expenses, your FSA deferral will be added back to your income. So, you need to enter your expenses regardless.
Did you "max out" the deferral and contribute $5000?
If you have only 1 child, you will not receive an additional tax benefit if you diverted $3000 or more. If you have 2 or more children, you may receive a tax benefit for additional expenditures.
If you are due an additional benefit, Turbo Tax will calculate that. I recommend that you enter what you paid, and be mindful that maxing out on an FSA will not produce an additional credit if you have 1 child.
See below for similar question:
https://ttlc.intuit.com/questions/3435214-i-have-a-5-000-childcare-fsa-but-spent-11-000-why-can-t-i-...
