The process of exchanging tickets at Kyoto Station to the airport is a bit complicated. The first time, exchange the e-voucher for a ticket to choose the departure date. You can do it a few days in advance because the line to exchange tickets is quite long. Passports with chips can be exchanged at the machine, otherwise you have to go to the counter. The second time, exchange for a ticket to choose the train to use on the day of the ticket. You must exchange this ticket before boarding the train and don't have to wait too long to exchange the ticket. Choose a departure about 7-10 minutes later and you can comfortably get on the train. The train to the airport comes every 30 minutes.