I get the following error, and I’ll include the function code below. I am using Flutter and the mailer library. For the password, I use an application-specific password.

I/flutter ( 7869): Caught MailerException: Authentication Failed (code: 535), response:
I/flutter ( 7869): < 5.7.8 Username and Password not accepted. For more information, go to

import 'dart:typed_data';
import 'package:mailer/mailer.dart';
import 'package:mailer/smtp_server.dart';
import 'dart:io';

class EmailService {
final String _username = '[email protected]';
final String _password = 'contra';

Future<void> sendEmailWithPdf(Uint8List pdfData) async {
final smtpServer = gmail(_username, _password);

// Crear un archivo temporal para almacenar el PDF
final tempFile = File('${Directory.systemTemp.path}/document.pdf');
await tempFile.writeAsBytes(pdfData);

final message = Message()
  ..from = Address(_username, '[email protected]')
  ..recipients.add('[email protected]') // Dirección de correo del destinatario
  ..subject = 'PDF Attachment :: 😀 :: ${DateTime.now()}'
  ..text = 'This is the plain text.nThis is line 2 of the text part.'
  ..attachments = [
    FileAttachment(tempFile)..fileName = 'document.pdf',
  ];

try {
  final sendReport = await send(message, smtpServer);
  print('Message sent: ' + sendReport.toString());
} on MailerException catch (e) {
  print('Message not sent.');
   print('Caught MailerException: ${e.toString()}');
  for (var p in e.problems) {
    print('Problem: ${p.code}: ${p.msg}');
  }

} finally {
  // Eliminar el archivo temporal después de enviar el correo
  tempFile.deleteSync();
}

thanks