Yes. The Izmir - Ayden motorway has tolls. You need to buy a HGS toll card from PTT or at the offices at the entrance to the motorway or some service stations. The sticker you place on your windscreen (behind your mirror) then it is automatically deducted from your card account. You decide how much to put on your card. As the toll is about 4.50/5.00tl you need to put enough to cover that and any return journey.
There is also a private toll, not covered by HGS, to go through the Gocek tunnel. The charge is 5.50tl
If you do not want to go through the tunnel, there is a road that goes over the hill but it takes about an extra 10 minutes and is winding.
If you are hiring a car the company should already have cover.