@1234C Please make sure you do the following:

1. Go to Profile tab and select E-file extensions for federal and state, if any.

2. Go to Input tab -left panel: Payments, Penalties, Extensions- -Extensions- Automatic Extension (4868) select 1, fill in the amount payment, if any, and select 1 for Extension Pursuant to Regulation 1.6081-5(a)

It should work.