NO, that is the normal thing to do. Can also do at any of the very few remaining VY/NorskeTog counters

There are also the socalled ´NO in a nutshell´ circular trips that go 1 way by train and other way by boat to amaze the sights of 1 fjord, whre NO is so famous for. The part by VY-train is paid for by your pass (if willing to use a passday for it)

Discounted tickets are available from a Norwegian ticket office (there's only a few) or by phone from Vy:

https://www.norwaysbest.com/flamsbana/timetable-and-fares/

Thank you for the answers.

Indeed, this was to book some of the legs of the Norway in a Nutshell tour. The company that sells the tour as a package (all legs are on public transport) does not give Interrail discounts. But you can book all the legs separately.

To help others in the future, for the trains (Oslo-Myrdal, Myrdal-Flåm and Voss-Bergen) I used the Entur call centre (+47 61 27 90 88). Very efficient, can be done in English, pay by credit card. They could book Interrail reservations on the normal trains as well as tickets on the Flåm railway (including the 30% Interrail discount). They could even book an Interrail reservation for a 1st class ticket holder and simultaneously book tickets and reservations for a non Interrail traveller.

Hello, I’m looking for a bit more information on booking Flåmsbana than I can find in this community Is it possible to reserve specific seats on the Flåmsbana? We’re heading to Norway in July 2024 - so at a really busy time. We know what time train we want to catch. And there are four of us, so we don’t want to leave it to chance and just hope to be able to sit together. If it is possible to reserve specific seats, do I do so via Entur? And which are the best/worst seats? Thanks!

The tickets we booked in 2022 had "free seating”, so it looks like there are no reserved seats. But they don't sell more tickets for a train than there are seats.

You can book by phone or by using the chat on entur.no.