JSON_Header Authorizations

function Test() { 
  ImportJSONISBN("https://api2.isbndb.com/book/9781260486230", "book")
}
  
function ImportJSONISBN(url, xpath, optional) {

  try{
  var headers = {
             "contentType": "application/json",
             "headers":{"Authorization": "xxxxxxxxxxxxxxxxxxxx"}  // 
             };

  var res = UrlFetchApp.fetch(url, headers);
  var content = res.getContentText();
  var json = JSON.parse(content);
  var patharray = xpath.split("/");
    
  for(var i=0;i<patharray.length;i++){
      json = json[patharray[i]];
    }
                
  if(typeof(json) === "undefined"){
      return "Node Not Available";
    } 
  else if(typeof(json) === "object"){
      var tempArr = [];
      if (optional === "debug") {
          for(var obj in json){
          tempArr.push([obj,json[obj]]);
          }}
        else {
          var sheet = SpreadsheetApp.getActiveSheet();
          var last = sheet.getLastColumn();
          var header = sheet.getRange(1, 1, 1, last).getValues()[0];
          for (var h = 3; h < header.length; h++) {
            tempArr.push(header[h] in json ? json[header[h]] : "-");
          }
        }
 
      return tempArr;
    } 
    
  else if(typeof(json) !== "object") {
      return json;
    }
  }
     
    catch(err){
      return "-";  
  }