Do you need cash to pay for Kansai Airport Rapid Service or Limited Express Haruka train from Kansai Intl Airport?

My family and I will be arriving in Kansai International Airport and plan to take either the Limited Express Haruka or Kansai Airport Rapid Service to Osaka Station.

We weren't planning to get yen in our home country (France) but to take out yen at a 7/11 ATM while we're in Japan. We also were planning to bring maybe around 100 euros in cash to exchange for yen if necessary.

But it seems like in order to take either of these trains, we'll have to pay in cash. Is that the case?

If it is, is it easy to get cash at the airport? I looked online and saw that there is a 7/11 ATM there, but is it easy to find?

Additional detail: I know there are sometimes ways to pay with credit card for digital tickets on iPhones, but we don't have iPhones.

by Catdress92