Basic URL storage to Google Sheet - Google App Script

/*
Instructions:
Follow all instructions in order.

Step 1: Go to code.google.com, create a new script and copy/paste this script to the editor.

Step 2: Select the save button next to Run (This is an important step, the script must be saved before deploying it)

Step 3: Select the big blue Deploy button on the top right corner and select New Deployment from the dropdown menu.

Step 4: Select the gear icon on the left corner and set type to Web App.

Step 5: Give the new deployment a description in the description field, select execute as Me (email address) and set who has access to Anyone (NOT ANYONE WITH A GOOGLE ACCOUNT, JUST ANYONE)

Step 6: Select Deploy and allow permissions. If it warns that the app is not secure just selet proceed.

Step 7: Copy the web app URL and paste them into the inworld scripts

Step 8: Proceed to the server script
*/

let ssNew; // To create and open a new spreadsheet
let ssId; // The id of the spreadsheet
let sheet; // the sheet number of the spreadsheet
let cell; // the cell range we want
let props; // properties of the Google App Script. Properties are like a memory bank for the script
let payload; // the payload of the POST back to the inworld script.The will be the body in http_request
let options; // list of options/methods for the POST  back to the inworld script
let response; // the POST made back to the inworld script

function doGet(e)
{

props = PropertiesService.getScriptProperties(); // Get current script properties. You can view properties in projetc settings, select the gear icon on the far left
const client_url = e.parameter.client_url; // The value of the client_url parameter from llHttpRequest


 if(e.parameter.client_url) // requests from the client will be picked up from this function
  {


    ssId = props.getProperty('ssId'); // get the spreadsheet id from properties
    ssNew = SpreadsheetApp.openById(ssId); // open the spreadsheet
    sheet = ssNew.getSheets()[0];  // Select the sheet number of the spreadsheet
    cell = sheet.getRange("A2"); // Select the data in the cell range

     // the payload of the POST back to the inworld script.The will be the body in http_request
    payload =
   {
     "server_url":cell.getValue() // send the value of the cell back to the script
   };

  // list of options/methods for the POST  back to the inworld script
      options =
   {
     "method" : "post",
     "payload" : payload
   };

// Make the POST made back to the inworld script. Similar method to llHttpRequest.
   response = UrlFetchApp.fetch(client_url,options);


  }

}

function doPost(e)  // requests from the server will be picked up from this function
{
  const server_url = e.parameter.url; // The URL of the server provided from llHTTPRequest
  props = PropertiesService.getScriptProperties(); // Get current script properties. You can view properties in projetc settings, select the gear icon on the far left

  ssId = props.getProperty('ssId');   // Get the id of the spreadsheet saved in your Google drive


  if(ssId) // if the spreadsheet is created
  {
   ssNew = SpreadsheetApp.openById(ssId); // Open the spreadsheet
   sheet = ssNew.getSheets()[0];  // Select the sheet number of the spreadsheet
   cell = sheet.getRange("A2"); // Select the cell range we want to use
    cell.clear();// clear the cell range
   cell.setValue(e.parameter.url); // set the data in the cell range
   SpreadsheetApp.flush(); // Applies all pending Spreadsheet changes immediately. URL change in spreadsheet might be slow without this function so keep it in.
   props.setProperty('Server URL',server_url); // Store the server url in properties


    // the payload of the POST back to the inworld script.The will be the body in http_request
    payload =
   {
     "url_added":server_url // send confirmation of server url added to the spreadsheet
   };

  // list of options/methods for the POST  back to the inworld script
      options =
   {
     "method" : "post",
     "payload" : payload
   };

// Make the POST made back to the inworld script. Similar method to llHttpRequest.
   response = UrlFetchApp.fetch(server_url,options);



  } // if(ssId)

  else // if spreadsheet is not created
  {
   const ssName = e.parameter.spreadsheet; //The name of the spreadsheed sent from llHttpRequest

    ssNew = SpreadsheetApp.create(ssName); // Create a spreadsheet in Google Drive with the spreadsheet name provided from llHttpRequest

   props.setProperty('ssId', ssNew.getId()); // Add the spreadsheet id to script properties

  // Lets add headers to the spreadsheet

   ssId = props.getProperty('ssId'); // get the spreadsheet id from properties
   ssNew = SpreadsheetApp.openById(ssId); // Open the spreadsheet
   sheet = ssNew.getSheets()[0];  // Select the sheet number of the spreadsheet
   cell = sheet.getRange("A1"); // Select the cell range we want to use
    cell.clear();// clear the cell range
   cell.setValue("Server URL"); // set the data in the cell range
   SpreadsheetApp.flush(); // Applies all pending Spreadsheet changes immediately.

   // Lets respond back to the inworld script

    // the payload of the POST back to the inworld script.The will be the body in http_request
    payload =
   {
     "SpreadsheetReady":"SpreadsheetReady" // send confirmation of spreadsheet creation back to the script
   };

  // list of options/methods for the POST  back to the inworld script
    options =
   {
     "method" : "post",
     "payload" : payload
   };

// Make the POST made back to the inworld script. Similar method to llHttpRequest.
  response = UrlFetchApp.fetch(server_url,options);  // POST back to the script the payload


  }


}