Arcade pop-up chart not showing the correct bar labels

[PauJuan]

Hi,

I am trying to configure a simple pop-up chart using an Arcadis template. I can retrieve values from the linked table using '$feature.FIELDNAME'. However, the labels in the resulting chart all show 'expr', rather than column names (see chart and code below).

return {
    type: 'media',
    // title : 'The title for all media in the element',
    attributes : {A : $feature.REACHSIMNO, B : 3, C : 4},  // replace this dictionary with your own key-value pairs
    mediaInfos: [{
        type : 'barchart', //linechart | barchart | piechart | columnchart
        title : 'The title for the chart in the element',
        caption : 'Optional caption',
        altText : '', // altText will be read by screen readers
        value : {
          fields: ["A", "B", "C"],  // choose what attributes to use in the chart
          //normalizeField : '',  // the name of the attribute to normalize by or value 
        }
}]
  }

Any ideas why this is the case? I would expect the labels to be A, B, C, etc.

Thanks for your help