We figured out. We set $0 for all the countries under Pricing and Availability -> Price Schedule. It seems like that is the place to set the up-front charge. Now, the app is free to download.

Hi Shirley, we are having the similar issue like you. Can you please tell where to change that price? We set monthly subscription with a one-month free trial, but the app is now asking for one-timer purchase on Apple store. Thank you.