First of all, amazing software!
As in the title, I bought the software on Steam but I did not receive the license key via the email (the one registered on Steam).
I already sent an email to firstname.lastname@example.org
Thanks for the help and have a nice day,
Meanwhile we had email contact, but for public information: A standalone license key is not created when you order on Steam. In that case you have a licensed version in your Steam library. But everyone who bought on Steam, can request a free standalone license by sending an email to email@example.com, giving full name and proof of purchase (e.g. screenshot from Steam purchase).