How could I get the receipt/invoice for the Turbotax service plan that I purchased?

Bank statement, maybe?  

To get to your order details, please follow the instructions below:

1. Sign on to https://myturbotax.intuit.com/
2. Scroll down to the bottom of the screen
3. On the section, Your tax returns & documents click on Show
4. Click on the Year 
5. Click on View order details

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