Every park pass comes with 3 fast passes. The app is the best way to reserve them.
In the app My Disney Experience
If you have Disney app you can do it there before your trip. Or they have kiosks in the park. Everyone gets 3 so choose wisely. There are workers to help you at the kiosks.
You can call customer service (reservations) or use the app, if I'm not mistaken they let you -each individual- have certain amount of fast passes per day. Also in the parks, each day when you visit it. Enjoy!
If you dt do it in the app, you can do it at a kiosk in the each park. However, i suggest you do it on the app or online before you get there. Sometimes they aren't available the day of because they are hot attraction
From the disney experience app
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