ReferenceError: "Sheets" is not defined

This is my first attempt with script editor. I was assigned to do a script to crate pivot table for google sheet.

  //creating pivot table through script editor for google sheet
  function addPivotTable() {

  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheetName = "Sheet1";

  // Create a new sheet which will contain our Pivot Table
  var pivotTableSheet = ss.insertSheet();
  var pivotTableSheetId = pivotTableSheet.getSheetId();

 // Add Pivot Table to new sheet
 // Meaning we send an 'updateCells' request to the Sheets API
 // Specifying via 'start' the sheet where we want to place our Pivot Table
 // And in 'rows' the parameters of our Pivot Table 

  var requests = [{
    // Meaning we send an 'updateCells' request to the Sheets API
    "updateCells": {
        // And in 'rows' the parameters of our Pivot Table 
       "rows": {
         "values": [
      {
         // Add Pivot Table to new sheet
        "pivotTable": {
          "source": {
            "sheetId": ss.getSheetByName(sheetName).getSheetId(),
            "startRowIndex": 0,
            "startColumnIndex": 0,
          },
          //create rows from the selected columns
          "rows": [
            {
              "sourceColumnOffset": 14,
              "showTotals": true,
              "sortOrder": "ASCENDING",   
            },
          ],
          //show values from the selected columns
          "values": [
            {
              "summarizeFunction": "COUNTA",
              "sourceColumnOffset": 10
            }
          ],
          //display in horizontal layout
          "valueLayout": "HORIZONTAL"
        }
      }
    ]
  },
  // Specifying via 'start' the sheet where we want to place our Pivot Table
  "start": {
    "sheetId": pivotTableSheetId,
  },
  "fields": "pivotTable"
}
 }];

  Sheets.Spreadsheets.batchUpdate({'requests': [requests]}, ss.getId());
}

Please do check my code and explain where did i went wrong as every time im running the script editor error telling sheet is not defined popup. "ReferenceError: "Sheets" is not defined. (line 46, file "Code")Dismiss"