Currently there are 11 native Telephoto Prime lenses for Panasonic GH5 and 7 of these lenses are autofocus (AF) type.
GH5 also has a sensor based image stabilization system which means that all of these lenses will be stabilized when used on GH5.
Since Panasonic GH5 has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 4 Telephoto Prime lenses with Weather Sealings.