How to send a receipts email in an online shop

[Dorony]

Hey,
How do I see the receipts for payments I received in my shop? And how can I be sure that a receipt email has been sent to the customer?
I saw in Shopify's help center and in YouTube videos that people talk about the POS app, but from what I understand it's mainly for physical sales. My shop is online, so how do I still generate receipts and see my receipts?
Should I download the POS app anyway to manage receipts from there, even though my shop is online? Or do I need another app? I don't see any mention of receipts anywhere in the admin area!

Thanks

[jenny123456778]

Hey

I am wondering the same.

Customers email us to ask for a receipt/ invoice.
I'm surprised this is not automated. 
Hoping for some assistance to this.