Not able to sum all the value of a field in recordType data

Hi, I am facing an issue where I want to add all the value of a column and display it on the top of the gridfield, The source of data is a recordType (Adding the code down below), Please help me with this.

{
  a!textField(
    label: "Sum Of Values",
    labelPosition: "JUSTIFIED",
    value: a!currency(isoCode: "USD", value: 0),
    readOnly: true
  ),
  a!gridField(
    labelPosition: "COLLAPSED",
    data: 'recordType!{b43afdfb-93b4-4d94-9708-ffa71f87754a}MWM Test',
    columns: {
      a!gridColumn(
        label: "Value",
        sortField: 'recordType!{b43afdfb-93b4-4d94-9708-ffa71f87754a}MWM Test.fields.{2682c5c7-76eb-4a9a-abf5-d409f2bc3f80}budget',
        value: a!currency(
          isoCode: "USD",
          value: fv!row['recordType!{b43afdfb-93b4-4d94-9708-ffa71f87754a}MWM Test.fields.{2682c5c7-76eb-4a9a-abf5-d409f2bc3f80}budget']
        ),
        align: "CENTER",
        width: "NARROW"
      )
    },
    pageSize: 100,
    selectable: true,
    selectionStyle: "ROW_HIGHLIGHT",
    selectionValue: {},
    selectionSaveInto: {},
    height: "MEDIUM_PLUS",
    showSearchBox: false,
    showExportButton: false,
    showRefreshButton: false
  )
}

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