I have this error exception when i try to create a menu into a spreadsheet.
Exception: No se puede usar SpreadsheetApp.getUi() desde este contexto. (línea 151, archivo "Código")
This the extract for my code:
function addRowTotals() {
 var ss = SpreadsheetApp.getActive();
 var sheet1 = ss.getSheetByName('Inventario');
 var lastRow = sheet1.getLastRow();
 var data = sheet1.getRange(2, 1, lastRow-1, 3).getValues();
 Logger.log(data);
 var totalsArray = [];
 data.forEach(function(row){
 var name = row[0];
 var cost = row[1];
 var quantity = row[2];
  var total = cost * quantity;
  //Logger.log(total);
  row.push(total);
  totalsArray.push([total]);
  Logger.log(row);
  });
Logger.log(totalsArray);
 //* Paste data back into a sheet
 sheet1.getRange(2, 4, lastRow - 1, 1).setValues(totalsArray);
 }
 // ***** Add menu
 function onOpen(){
 var ui = SpreadsheetApp.getUi();
 ui.createMenu("Custom Menu")
.addItem("Add Row Totals", "addRowTotals")
.addToUi();
 }