Where can I find the Steam key that was advertised in the purchase?
During purchase it tells me: "Download this tool by purchasing it for 10 USD or more. You will receive a Steam key with your purchase."

I checked the downloads Section, but nothing can be found there? Is this miscommunication, or should I find the key elsewhere/is is e-mailed at a later time?

Thx for your help,
Kniti

Follow this instruction https://itch.io/t/67604/how-to-get-a-steam-key-from-your-itchio-purchase

Thx for the link. This works for any other software I bought on this Plattform, but not pixel composer...