Entity filter state_filter, only show when state is other than

Hi,

I’m trying to use the entity filter card and want to only show the card when the state is other than Geen

type: entity-filter
entities:
  - sensor.rd4_vandaag
state_filter:
  - "not 'Geen'"
card:
  type: entities
show_empty: false

What am I doing wrong?

type: entity-filter
entities:
  - sensor.rd4_vandaag
state_filter:
  - operator: "!="
    value: "Geen"
card:
  type: entities
show_empty: false

Reference

Entity Filter Card - Examples