How to Call JSON Web Service to Populate Google Sheet

function getData() {
  
  // DECLARE SHEET
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var mainSheet = ss.getSheetByName("MAIN");
  
  // GET CATEGORY VALUE
  var race_year = mainSheet.getRange(3, 2).getValue();
  var race_num = mainSheet.getRange(2, 2).getValue();
  var race_laps = mainSheet.getRange(1, 2).getValue();
  
  //CLEAR QUESTION AND ANSWER
  mainSheet.getRange('A7:DC27').clear();
  
  //INSERT LAP NUMBERS
  for (var j = 1; j <= race_laps; j++)
  {
       mainSheet.getRange(7, j + 1).setValue([j]); 
       SpreadsheetApp.flush();
  }

  // URL
  var URL_STRING = "http://ergast.com/api/f1/" + race_year + "/" + race_num + "/drivers.json"

  console.log('URL_STRING ' + URL_STRING);


  //CALL API
  var response = UrlFetchApp.fetch(URL_STRING);
  var json = response.getContentText();
  var data = JSON.parse(json);
  
  var drivers = [];
  
  //GET DRIVERS
  for (var i = 0; i < data.MRData.DriverTable.Drivers.length; i++) 
  { 
    var drivers_Array = data.MRData.DriverTable.Drivers;      
    
    //STORING DRIVERS
    drivers.push(drivers_Array[i].driverId);

    mainSheet.getRange(8 + i, 1).setValue([drivers_Array[i].driverId]);
    SpreadsheetApp.flush();
  }

  for (var j = 1; j <= race_laps; j++)
  {
    // URL
    var URL_STRING = "http://ergast.com/api/f1/" + race_year + "/" + race_num + "/laps/" + j + ".json";

    console.log('URL_STRING ' + URL_STRING);

    //CALL API
    var response = UrlFetchApp.fetch(URL_STRING);
    var json = response.getContentText();
    var data = JSON.parse(json);

    var laptime_array = data.MRData.RaceTable.Races[0].Laps[0].Timings;

    for (var y = 0; y < drivers.length; y++)
    {
      var driver_id = drivers[y];

      console.log('laptimes ' + laptime_array.length);

      //GET LAP TIMES
      for (var i = 0; i < laptime_array.length; i++) 
      {      
        if (laptime_array[i]["driverId"] == driver_id)
        {
          var laptime = laptime_array[i]["time"];
          const time_array = laptime.split(":");
          const seconds = time_array[0]*60+(+time_array[1]);
          mainSheet.getRange(8 + y, j + 1).setValue([seconds]);
          SpreadsheetApp.flush();
          break;
        }

      }
    }
 
  }
  
}