The image training in Leonardo with the free version allows only one "set of models" per month!
But you can make a kind of training on the fly by putting several images as here!
There I put only 2 but you can put as many as you want (max 30) the ideal being 8-15 according to the FAQ! https://app.leonardo.ai/faq
Yep, formally it's "Dalle.e"...any regulate just a prompt and press Enter!
Free and infinite! Only one format 1024x 1024... https://www.bing.com/create