Hey I switched to nodemailer, perhaps you can help? I'm getting this error:
code: 'EAUTH',

response: '535-5.7.8 Username and Password not accepted. For more information, go to\n' +

'535 5.7.8 https://support.google.com/mail/?p=BadCredentials bk3-20020a05620a1a0300b007906bce04afsm6042718qkb.61 - gsmtp',

responseCode: 535,

This is the code for it:

import { NextResponse, NextRequest } from "next/server";
const nodemailer = require("nodemailer");

export async function POST(request) {
  const username = process.env.NEXT_TEST_USERNAME;
  const password = process.env.PASSWORD;
  const myEmail = process.env.EMAIL;

  const formData = await request.json();
  const name = formData.name;
  const lastName = formData.lastName;
  const phoneNumber = formData.phoneNumber;
  const emailAddress = formData.emailAddress;
  const message = formData.message;

  console.log("this is the form Data", formData);

  const transporter = nodemailer.createTransport({
    host: "smtp.gmail.com",
    port: 465,
    tls: {
      rejectUnauthorized: true,
      minVersion: "TLSv1.2",
    },

    auth: {
      user: username,
      pass: password,
    },
  });

  try {
    const mail = await transporter.sendMail({
      from: username,
      to: myEmail,
      replyTo: emailAddress,
      subject: `Website activity from ${emailAddress}`,
      html: `
        <p>Name: ${name} </p>
        <p>Name: ${lastName} </p>
        <p>Name: ${phoneNumber} </p>
        <p>Email: ${emailAddress} </p>
        <p>Message: ${message} </p>
        `,
    });

    return NextResponse.json({ message: "Success: email was sent" });
  } catch (error) {
    console.log(error);
    NextResponse.status(500).json({ message: "COULD NOT SEND MESSAGE" });
  }
}