如何在Nest Js的Mailer模板中添加子文件夹

import { MailerService } from '@nestjs-modules/mailer';
import { Injectable } from '@nestjs/common';

@Injectable()
export class MailService {
  constructor(private readonly mailerService: MailerService) {}

  async sendWelcomeEmail(user: any): Promise<void> {
    await this.mailerService.sendMail({
      to: user.email,
      subject: 'Welcome to our platform',
      template: './templates/welcome', // 主模板文件路径
      context: {
        // 主模板中使用的变量
        username: user.username,
      },
      attachments: [
        {
          filename: 'invoice.pdf',
          path: './templates/invoices/invoice.pdf', // 子模板文件路径
        },
      ],
    });
  }
}