Google calendar integration fails

Configuration Frontend
11

ok here is my code

title: Skank
path: persoon1
theme: ios-dark-mode
cards:
  - type: horizontal-stack
    cards:
      - type: picture
        image: /local/skank.jpg
      - type: entities
        entities:
          - type: 'custom:atomic-calendar'
            dateColor: white
            dateSize: 90
            dayWrapperLineColor: orange
            dimFinishedEvents: true
            entities:
              - entity: calendar.skank
            eventBarColor: orange
            finishedEventFilter: grayscale(100%)
            finishedEventOpacity: 0.3
            fullDayEventText: All day
            locationIconColor: 'rgb(255, 255, 255)'
            locationLinkColor: lightyellow
            locationTextSize: 90
            maxDaysToShow: 7
            progressBarColor: yellow
            showColors: withe
            showCurrentEventLine: false
            showLocation: true
            showMonth: false
            showProgressBar: true
            timeColor: white
            timeSize: 90
            title: Trenings Kalender Fotball
            titleColor: white
            titleSize: 100
            untilText: Until

Now im getting

pressing F says

Failed to load resource: the server responded with a status of 400 (Bad Request)