It has two pages
Stores product details and their Price and GST Percentage
Here's where the Billing for the products are made Pre defined all products are shown first you can choose ADD to add the items to bill There's also a Search commmand where it easily searches according to Product name or product code.
Then after adding you can mention the quantity (Default is 1 after added)
While doing adding and Quantity changes the Total Money and Total Quantites will be updated simultaneously.