A psychotherapist is not always strictly required, but it depends on your goal, setting, and local rules. If you want a clinical pathway or future insurance reimbursement, expect that a licensed psychotherapist with specific training will be needed.
Where clinical psychedelic psychotherapy is not available, some choose non-medical facilitators for legal options. If you go that route, verify solid training, clear screening, preparation and integration support, ethics, and a plan for adverse reactions or referrals.
Regulations and reimbursement policies vary and change. I cannot verify how this will work in the Netherlands yet. For context, this overview on whether a psychotherapist is needed in psychedelic therapy may help: read more here.
Choose the route that fits your goals and complies with local law. Stay informed and proceed carefully.