All conference delegates travelling to the Netherlands must present a passport (or an approved identity card for EU citizens). Many countries require a visa to enter the Netherlands. Delegates are encouraged to apply for visas early (at least two months before departure) and to ensure all requested documentation is submitted with the application for a Schengen visa (Visa C). Applications must be submitted in person at the representation of the Netherlands in the respective countries, or at a Schengen partner representation if the Netherlands does not have representation in that country. Delegates are urged to contact their nearest Dutch embassy or consulate as early as possible to determine where to apply and how long the process will take.

Where can I get information?
Ministry of Foreign Affairs, Kingdom of the Netherlands:
https://www.government.nl/topics/embassies-consulates-and-other-representations

Search for the Dutch embassy or consulate in your country and contact them. You need to apply for a Travel Visa C (Tourist Visa).

Travel visa (Visa C): if you intend to go to the Netherlands as a tourist, to visit friends or on a business trip for a period not exceeding 90 days and your country does not participate in the Visa Waiver Programme, you need a Schengen travel visa (Visa C). This visa is not a work permit.