With the Disney Application you are able to link a ticket and reserve up to 3 fast pass per day at one park. You are only allowed 1 fast pass per attraction per day. When you are at the park they are loaded to your magic bands or card and you go at the specific 1 hour window allotted. After these 3 are used one can reserve 1 at a time. Very easy and useful, however some rides such as flight of passage, the queue is really amazing so if you can catch it with 70 minutes waiting or less, it is worth going through the queue.
You can get 3 before showing up for your visit. After you use your first three you can get one at a time.
They have kiosks st up around the park to get them.
Every ticket comes with a few fast passes which you can schedule for rides you would like to go on. I believe you can purchase more but typically they come with 3 per ticket.
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