Just some comments on Felix Miller’s helpful tipps:

-Regarding Hurtigruten/ Havila: Price for a bicycle is 250 NOK per day. (Quite expansive for a short trip like Vadsø – Kirkenes.)
https://www.hurtigruten.no/praktisk-informasjon2/den-originale-kystreisen/#livet-om-bord
https://www.havilavoyages.com/faq

-Regarding the Vy app: I found out that it’s probably easier to use entur.no (or Entur app). You can book pretty everything there, and if you need any help, they’ll help you in the chat.