Ejerforeningen - would that be the condo board of directors ?
In Norway we have a law that regulates condo rentals - Borettslagsloven. Any rental (short term or long term) will have to be within these laws and regulations. airbnb of course is something new and not directly covered in the legislation, so normally the legislation concerning general rental will apply.
Full time airbnb rental may be considered/defined as hotel business and the condo rules may have a clause excluding running a business on the premises. There are many pitfalls
City councils can set their own rules and regulations. There are many pitfalls and I use to say we are on borrowed time.