Generally speaking, Norway FSA-regulated broker profile will be found at the Finanstilsynet's registry page on Norway FSA website. Try to find it and check if it will match the info from the broker website.
The detailed steps are as below:
1. Find the FT number(preferred) or name of the forex broker, which you can get from the broker's website;
2. Enter the FT number or name into the search bar on https://www.finanstilsynet.no/en/finanstilsynets-registry/ ;

3. And you'll get the broker's profile on Norway FSA website. At this time you need to check if the broker is an 'Investment firm' and has the authorization to provide 'No 4: Foreign exchange services connected to the provision of investment services' under 'Ancillary services, Securities Trading Act § 2-1 (2)';

4. If all the above steps have been done, don't forget to check the most important information: check if the firm details published on Norway FSA website matches the ones you'll go to trade with, especially the website and email etc. If no, please keep away the broker because it's probably an unauthorized firm and your money will fall in danger.
If the broker is an EEA authorised firm, you need to check further information in its home state regulator.
