code: def send_reset_password_instructions(self, user):
          
          token = self.security_utils_service.generate_reset_password_token(user)
          reset_link = url_for('security_controller.reset_password',
                               token=token, _external=True)
          self.send_mail(
              _('flask_unchained.bundles.security:email_subject.reset_password_instructions'),
              to=user.email,
              template='security/email/reset_password_instructions.html',
              user=user,
              reset_link=reset_link)
          reset_password_instructions_sent.send(app._get_current_object(),
                                                user=user, token=token)
docs: Sends the reset password instructions email for the specified user.
  
          Sends signal `reset_password_instructions_sent`.
  
          :param user: The user to send the instructions to.