Why did my credit card get charged twice after integrating with Printify?

[AnthonyHou]

Hi - I recently integrated my shopify store with Printify and when placing an order to test the order process flow etc, I noticed that my credit card was charged twice. Why is that? 

I did use the same credit card, that I have attached to my printify wallet, to make this recent purchase.  

Any clarity on this would be helpful for my understanding.