Whenever I try to go to the "Tax Paid by Installments" section, I get directed to the "Please tell us about your dependents" section. What am I missing?

To enter your Tax Paid by Instalments, in the sidebar or TurboTax Online:

Go to Deductions > Payments Profile > click on the Payments Profile that appears and you will land on the page "Your Payments Profile for 2018". Check the box beside Paid tax instalments for this year, then continue to the page "Paid tax instalments this year".