organization_user_idto identify and link your profiles on both platforms.
upsert_modeto true. Otherwise, when a consent is collected but the
organization_user_idvalue does not match with any contact in Sendinblue, the consent update will not be propagated to Sendinblue.
propertiesobject you need use the id
EMAIL_CAMPAIGNS_SUBSCRIBEDand map it with a purpose or a preference value from your PMP.