You must request prior authorization from the Medical Adviser of the Society for certain medical benefits (e.g.: psychotherapy fees, transport, cures, prosthetic appliances, etc.) This is clearly stated in Annex III of the internal Rules and in the relative page dealing with reimbursements under the main heading My Benefits.
You should do this before incurring any expenses, by submitting your prescription with a medical report (diagnosis/medical reason) for authorization to the Medical Adviser, per email: firstname.lastname@example.org or per regular mail:
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