Currently there are 9 native Macro Prime lenses for Sony A7S III and 5 of these lenses are autofocus (AF) type.
A7S III also has a sensor based image stabilization system which means that all of these lenses will be stabilized when used on A7S III.
Since Sony A7S III has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 4 Macro Prime lenses with Weather Sealings.