Workflow to create a T-shirt design

So I'd like to create a T-shirt design using Comfy-ui for a team I coach. I've tried giving it the team logo and then telling it a design idea but I can't seem to get a png output with an alpha background. I also need to iterate on it and tell it which fonts to use. Is there a workflow someone has that would be good at this or is there some other tool other than comfyui I should try. I don't want to use some web editor. I want this to run locally