In Jain Dharma, agnikāy jīva are found in the fire-bodied forms of fire in this loka—for example, ordinary flame, burning fire, and similar fire manifestations. Their presence is not identified just by looking at brightness or heat.

So the important distinction is:

• Fire on earth = can be a manifestation where agnikāy jīva may exist.
• Stars = in Jain cosmology, they are jyotishka luminous celestial bodies, not agnikāy.

So when you say “fire is there in every star,” that is a physical/scientific description, but in Jain classification a star is not the same as agni-tattva fire-body. Therefore, we do not say agnikāy jīva are in stars.

In simple words: All shining or hot things are not agnikāy. Only that fire-body which belongs to the Jain classification of agni-kāy contains agnikāy jīva.

If you want, I can also explain the difference between agnikāy, tejaskāy, and jyotishka in Jainism.