For single use licenses:
When you are logged into your account, select the main menu located in the upper right-hand corner of the site and go to “Licenses”. Select the “...” next to the license in question and then select “Receipt.” You’ll then be able to download the receipt as a PDF.
For subscriptions:
When you are logged into your account, select the main menu located in the upper right-hand corner of the site and select "Account", and then "Subscriptions" from the menu to the left. You can then expand the “Receipts” section to view and download your receipts.