For your customers to receive email notification about the referral program on your store you need to activate the Email Automation App - Foxx. With this app your customers will be updated when the customer they invited has made a purchase, and also you can send super targeted automated emails that drive sales using the Foxx application.
Go to the admin interface using this link : https://app.trybeans.com/
Now click on the Add button and add the Foxx application, you will see the set of rules available on the application, you need to activate the rules and also set the frequency according to how you want your customer's to receive notifications.
Click on this link to install the app : https://connect.trybeans.com/cms/foxx/ After Installing the app you go to the trellis app section here : https://bamboo.trybeans.com/trellis and activate the Foxx application. You can read more on the rules of Foxx here: https://help.trybeans.com/foxx/rules