Why EmailMultiAlternatives Not Sending Email?

Question

I'm trying to send a message to an email address with a pdf attachment. The letter doesn't come on mail. What's wrong in my code, please tell me?

base_path = 'http://127.0.0.1:8000/'

t = render_to_string(
    'pdf_template_nds.html',
    {
        'payment': payment,
        'date_pdf': date_pdf,
        'count': count,
        'sum_pdf': sum_pdf,
        'sum_final': sum_final,
        'sum_final_capitalize': sum_final_capitalize,
        'sum_nds': sum_nds,
    }
)
HTML(string=t, base_url=base_path).write_pdf(
    f'nds.pdf',
    presentational_hints=True
)


email = EmailMultiAlternatives(
    'Subject here', 'Here is the message.', '[email protected]',
    ['[email protected]'])
email.attach_file('nds.pdf')
email.send()