Artillery Fire self-propelled guns / heavy mortar without spotter? (clarified)

Hi,

i'm a little confused. A self-propelled gun is in Artillery category. so right, so good. it count's as Medium Gun in most cases
Medium and Heavy Guns only can only use indirect fire (Rulebook p. 40). also so right so good.

Am i right, that i.e. a M7 Priest if it has line of sight to a target, it need an observer to? or can it make a indirect fire on it own?

The same question for a Mortar.

Thx for helping me.

if the Priest has line of sight it fires direct HE

Apart from light mortars, they need a spotter.

ok that sounds good. So a self-propelled can use direct fire like a tank & indirect fire with a artillery spotter, correct

Yep.

thx alot, so the question is cleared