Stacked column chart to use column A as header in App Script

I have this table and the chart I want as below:

To acheive this I have to switch rows/columns, and use column A as headers.

However I cannot find the corresponding command for the checkbox "Use column A as headers".

This is my script:

function myFunction() {
  const sheetTest = SpreadsheetApp.getActive().getSheetByName("test");

  const numRows = sheetTest.getLastRow();     // e.g. 9
  const numCols = sheetTest.getLastColumn();  // e.g. 3

  const chartRange = sheetTest.getRange(1, 1, numRows, numCols);
  const chart = sheetTest.newChart()
    .asColumnChart()
    .addRange(chartRange)
    .setStacked()
    .setPosition(1, 4, 0, 0)
    .setTransposeRowsAndColumns(true)
    .build();

  sheetTest.insertChart(chart);
}

This is what it produces, just one more step and it'd be perfect as you can see the headers are missing

In your script, how about using setNumHeaders as follows?

Modified script:

function myFunction() {
  const sheetTest = SpreadsheetApp.getActive().getSheetByName("test");

  const numRows = sheetTest.getLastRow();     // e.g. 9
  const numCols = sheetTest.getLastColumn();  // e.g. 3

  const chartRange = sheetTest.getRange(1, 1, numRows, numCols);
  const chart = sheetTest.newChart()
    .asColumnChart()
    .addRange(chartRange)
    .setStacked()
    .setPosition(1, 4, 0, 0)
    .setTransposeRowsAndColumns(true)
    .setNumHeaders(1) // Added
    .build();

  sheetTest.insertChart(chart);
}

Testing:

When this modified script is used, the following result is obtained.

Reference

• setNumHeaders(headers)