Stars are not actually gaseous, they are plasmas, ie highly ionized. Hence, the entire star is highly conductive and does not easily develop a voltage difference via friction needed for lighting. On the other hand, stellar atmospheres have strong magnetic fields which reconnect, and that causes strong voltage spikes that generate high energy electrons. On the Earth we would call streams of high energy electrons lightning, but on the sun we call them flares.

Stars are not actually gaseous, they are plasmas, i.e., highly ionized. Hence, the entire star is highly conductive and does not easily develop the voltage difference via friction needed for lightning like that in our atmosphere. On the other hand, stellar atmospheres have strong magnetic fields which reconnect, and that causes strong voltage spikes that generate high energy electrons. On the Earth we would call streams of high energy electrons lightning, but on the sun we call them flares.