Code.gs

const SHEET_NAME = 'Form Responses 1';

function doGet(e) {
  const sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(SHEET_NAME);
  const [headers, ...rows] = sheet.getDataRange().getValues();

  const data = rows
    .filter(row => row.some(cell => cell !== ''))
    .map(row => {
      const obj = {};
      headers.forEach((h, i) => { obj[h] = row[i]; });
      return obj;
    });

  const json = JSON.stringify(data);
  const callback = e.parameter.callback;
  if (callback) {
    return ContentService
      .createTextOutput(`${callback}(${json})`)
      .setMimeType(ContentService.MimeType.JAVASCRIPT);
  }
  return ContentService
    .createTextOutput(json)
    .setMimeType(ContentService.MimeType.JSON);
}