Selling Output as NFT

Hello people,

I am new here and wanted to ask about the legal situation in the use of images.
If I generate images with the stable diffusion demo, do I have the right to sell these images as NFTS or as art?
Who owns the rights to the output of the stable diffusion demo?
Is the legal basis different if I modify the model and create images on my own computer?
I hope you guys can help me.
Kind regards