Receipts are handled via your Stripe dashboard. You can access your Stripe account by logging in at https://dashboard.stripe.com/login and using the login information you created when connecting Stripe to EventCreate.
Once you login to Stripe, you should see the dashboard. There is a settings menu (gear icon) in the upper right corner:
Scroll down to Business settings > Your business and choose Customer Emails:
Choose which emails to automatically send: