After a few successful sales, I now received a message from Fiverr stating that I need to send them a copy of my passport in order to proceed selling on the platform.
By Dutch law (which apply to me as a citizen of The Netherlands and who works there), a company such as Fiverr is not allowed to require a copy of identification. Only governmental institutions may require this. A company may ask for a copy of the ID, but I should be free to decline this request. As a matter of fact, it is explicitly advised by our own government to never share an ID with unauthorized organizations, since the more places have a copy your ID stored, the greater the risk of a criminal gaining access to it and abusing it for identity theft.
So how do I circumvent the passport requirement? There must be a way, for Fiverr to be able to legally operate in my country.