Hi Jana Krahulcova,
Depending on your employment and residential circumstances you must be liable to pay UK national insurance for the first 52 weeks working overseas if your employer is deducting NI. You can discuss this further with your employer as you are also now subject to the Norwegian government rules.
Please see paragraphs in the link attached under
National Insurance for workers from the UK working in the EU, Gibraltar, Iceland, Liechtenstein, Norway, or Switzerland
“If you go to work in Iceland, Liechtenstein, or Norway”
and also
“If you are not covered by a social security agreement”
Thank you.