USM allows you to keep a record of all the items available in the store.This feature is available in Inventory module which can be accessed by clicking on the menu bar on the right of the screen.
Step 1. Click on the menu bar on the top right of the screen and select the Inventory module.
Step 2. Click on the option Store Items on the left of the screen.
Step 3. Click on the option Add New Items on the top right of the screen.
Step 4. A pop up window will appear on the screen.Fill the form. After filling the form,click on the save option on the bottom of the dialog box.