In the Netherlands, the only clear legal consumer route is magic truffles. They are lawful to buy and possess and are sold in smartshops and by some online retailers.
Grow kits are legal to purchase, but once mushrooms actually grow, possessing them is illegal. Enforcement can vary and any sharing or selling carries significant legal risk.
Isolated psilocybin in powders, capsules, or extracts is illegal. Licensed research may use it under strict permits, which are not available to the public. Laws can change, and I cannot verify current enforcement practices, so check the latest official information.
For a concise overview of these options and their status, see this Q&A: legal access to psilocybin in the Netherlands.
Stay safe and within the law.