As the reply here is very specific, yet if people who do their due diligence and search for the topic, will find this post, I’ll ad that if you have a one country pass for Sweden, you can buy a seat reservation to Riksgränsen station and get a normal ticket to Narvik.
This a generally good advice, I am basically using the same trick to not use a home bound/outbound travel day by going to Narvik. My home country is Norway.
You can also do this if you want to have a break/sleepover on your home bound/outbound journey. I usually buy tickets to/from Ed and have a stop in Oslo on my way to from Bergen/Göteborg.
Thank you very much, AnnaB.
If you are going from Germany to Sweden and Norway you need a global pass.