function doPost(e) {
  var data = JSON.parse(e.postData.contents);
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  if (data.action === "save_pcr") {
    var sheet = ss.getSheetByName("PCR_Records") || ss.insertSheet("PCR_Records");
    sheet.appendRow([
      data.payload.pcrNo, data.payload.date, data.payload.timeCall,
      data.payload.ambulance, data.payload.officerLeader, data.payload.patientName,
      data.payload.triageLevel, data.payload.chiefComplaint, data.payload.destinationHospital,
      new Date().toLocaleString("th-TH")
    ]);
  }
  return ContentService.createTextOutput(JSON.stringify({success: true})).setMimeType(ContentService.MimeType.JSON);
}