You will find the option "Prompt to enter a sale price for products with $0 retail price during sale"
Please select the option and make sure you save the changes on the General settings page.
Once done, please process a Refresh data on your PC or a Data sync on your iPad.
On your PC/Mac, go to Point of Sale > Cash Register and you will see REFRESH DATA. Click on this to re-load the data from Hike on your browser.
On your iPad/Android tablet, from the expanded menu, click Settings, choose General, and click on Data Sync.