code.gs

var sheet_id = "YOUR_GOOGLE_SHEET_ID";  // Google Sheet ID
var ss = SpreadsheetApp.openById(sheet_id);
var sheet = ss.getSheets()[0];  // Get the first sheet in the spreadsheet

/** 
 * Handles HTTP GET requests.
 * Expected parameter: ?read=question
 */
function doGet(e) {
  var arg = e.parameter.read;
  
  // If no valid parameter is provided
  if (arg == undefined){
    return ContentService.createTextOutput("error: invalid request");
  }

  // If the request is for a question, return a new question
  if (arg == "question"){
    return getIter();
  }

  // For any other unexpected request
  return ContentService.createTextOutput("error: unexpected request"); 
}

/**
 * Finds the next question, marks it as shown, and returns its data.
 */
function getIter() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  
  var row = 2;  // Start checking from row 2 (assuming row 1 is header)

  // Find the first row in column H without a checkmark
  while (sheet.getRange("H" + row).getValue() !== "") {
    row++; 
  }

  // Get question data from columns A, B, and G for the current row
  var question = sheet.getRange("B" + row).getDisplayValue(); 
  var difficulty = sheet.getRange("G" + row).getDisplayValue(); 
  var question_id = sheet.getRange("A" + row).getDisplayValue(); 

  // Mark this question as used by putting a checkmark in column H
  sheet.getRange("H" + row).setValue("✓"); 

  // Prepare the response string
  var res = "Question #" + question_id + " Difficulty : " + difficulty + "\n\n" + question;
  
  Logger.log(res);

  // Return the result as a plain text HTTP response
  return ContentService.createTextOutput(res);
}