1. Click on your Steam name, located at the top right of the Steam client.
2. Select the option for Account Details.
3. From your Account Details page, click View purchase history.
4. On this page, you should see details of the purchases you have made with your Steam account.
5. Finally, click on the name of the Item to display the proof of purchase.
Please note that we will need an uncropped and unedited screenshot in order to provide you with assistance.
If you are on PC, you can follow this link for directions on how to take a screenshot.
PC Screenshot Guide
If you are on Mac, you can follow this link for directions on how to take a screenshot.
Mac Screenshot Guide