These are usually installed on a pitched roof.
Vent bathroom fan through roof or wall.
Will be usually fed.
In order to accomplish this the roof has to have a hole cut in it.
Broan sells an inexpensive model which is probably available at any big box store.
Typically an exhaust fan that is vented through the roof has a roof hood or roof cap which allows air to exhaust but provides protection from wind blown rain.
This involves running ductwork from the fan usually though an attic and out through the roof.
From up on the roof use a jigsaw or reciprocating saw to cut a 4 in.
If you want to vent a bathroom fan through an exterior wall you will have to cut a 3 inch or 4 inch hole with a hole saw drill bit.
Start in the attic and drill a hole through the roof in the desired vent location.
Leave the drill bit sticking through the roof so you can find the hole.
It is because of this that many builders tend to advise against this method.
Going to the soffet is 12 feet.
The fan will need to be an inline fan with ducting and a grill in the bathroom.
If your exterior siding is vinyl or fiber cement you will have an easier time cutting the hole.
Try to keep it close to the fan location.