function sendEmails() {
  const sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  const data = sheet.getDataRange().getValues();
  
  for (let i = 0; i < data.length; i++) {
    const row = data[i];
    const email = row[0];
    const username = row[1];
    const password = row[2];

    if (email) {
      const subject = "ICPC Minya — Creativa Wi-Fi Credentials";

      const htmlMessage = `
        
Dear Participant,

        
Welcome to the ICPC Minya session at Creativa Hub!

        
Here are your personal Wi-Fi credentials:
        

          
Username: ${username}
          
Password: ${password}
        

        
⚠️ Please note:
        

          
Do not share your credentials with anyone.
          
Do not use hotspot or share your connection.
          
Connect only on the device you’ll be using during the session.
        

        
Best regards,

        ICPC Minya Team
      `;

      MailApp.sendEmail({
        to: email,
        subject: subject,
        htmlBody: htmlMessage
      });
    }
  }
}