This page: https://x4fab.itch.io/ac-content-manager claimed this product came with a Steam key. Purchased, went to plug the key into Steam, and Steam says the key I was provided is invalid. Turns out that key isn't a Steam key, you plug it into Content manager itself (a download link is provided) to upgrade from the Free to the Paid version. Could be made more clear, please correct the line that says Steam key.