Train from Gothenburg to Oslo mid September

www.vy.no

Been trying the above website. I only get an error message

The above is the right website, but it's giving me an error message as well. I know it was working a few days ago.
It is a long distance commuter style train, so booking is not essential.

But for anyone wanting to reserve elsewhere on the Vy network it would be very useful to resolve the website error.

https://www.vy.se/en also sells them without but without seat reservation, I think they only reserve seats in car 5 so you could just choose another car when you travel.

Need suggestions train site seems to indicate we can only buy in person?

For any date or just specific dates?

The above is the right website, but it's giving me an error message as
well.

I got some error too, refreshed the page, solved a puzzle and got in.

An hour later and vy Norway is working now. They've introduced a human verification process over the weekend.

If Vy's site isn't working you can also use www.sj.se