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



Leonardo 15 colored complex engine

Big Zoom: https://imgbox.com/g/B32mIHyAUX