This is a proof of concept uniting different picture I found out about getting a transparent body.
You can have different object to replace the belly, like :

• colored, BASE PROMPT :

<COLOR> belly, <COLOR> belly, no ???????, exposed breast,

• skeleton pattern :

see-through, see-through breast, x-ray, inside skeleton, breast skeleton,

• Lava lamp pattern :

<COLOR> lava, lava lamp, lava lamp belly, see-through, transparent belly,

• Aquarium pattern :

glowing belly, aquarium belly, aquarium inside body, algae inside belly,

Negative prompt to add :

out of frame, belly shot, tan, tan body, close shot,

Specification of each "transparent" tag :

To generate a skeleton view, you should use x-ray tag.

To any other item inside, you should use see-through and see-through breast if you want the pattern to extends up to it.

The lora Isn't stable and may be unpredictable with some prompt.