Hi there, I have a friend travelling with an interail pass from Zurich to Munich, 14 August, departure 7.33am.

She’s trying to reserve a seat (family of 4) but the option to continue is greyed out on Rail Europe - ie she can see the train  and select it but the seat reservation isn’t possible.

I’m assuming it’s because theres no charge. Where’s the best place to book these seat reservations please?

Thanks.