Hi Gerda,
GCU has had an AI policy in place for a couple of years now and I recommend taking a moment to read it.
You'll find that GCU does not accept straight AI generated work. Artists using AI software must add value by significantly making artistic changes to the piece, and GCU requires a link to the original AI creation to ensure during review that added value is sufficient.
Many artists, myself included, have dabbled in AI purely as a fun way to create. The artist's heart is one that should always explore and grow.
GCU's AI Policy for submissions:
http://www.greetingcarduniverse.com/forum/yabb2/YaBB.pl?num=1686087460