Well if they think they want to "contribute" with AI work to a charity project, that´s their choice. I think I have a bit experience in that and can see what is AI normally, and I would not take it.
I wrote to alot of artists and asked them. All people that don´t do AI art, only handmade art. And you can tell the typical style of these people. So let´s see what they send me.

And it´s not like they can earn anything with my project. The income will go to charity.

Sorry to say, but I don´t think it´s very nice that you are trying to promote your affiliate link below a charity project.