I am was having the same problem, but I was using TurboTax Desktop and these instructions seem to be for TurboTax Online. This is how I got to a similar place using the Desktop version:
1) In the Toolbar at the top of the TurboTax window click "Search Topics". It is left of the middle, don't confuse it with "Search" at the far right.
2) Enter "1040-es", click the first item and you are taken directly to the right place to answer questions and get the vouchers added to your return. Note that is the only option, you can't print them directly from that screen.
