Target group traffic port override for auto scaling group

Hi.
We have a following situation.
Our target group port is set to 443 but our backend is listening on port 80.
Using AWS console we can easily override a traffic port during instance registration to the target group. However we are unable to override traffic port using aws_autoscaling_attachment.
Whatever we do the autoscaling instances are always set to send traffic to port 443.

Is there any way to tell terraform to override traffic port during aws_autoscaling_attachmen event.

Here is a relevant terraform code:

resource “aws_alb_target_group” “test” { name = “test” port = 443 protocol = “HTTPS” vpc_id = “${var.vpc_id}” deregistration_delay = 80
stickiness {
type = “lb_cookie”
}

health_check {                                                                                                                                                                                                                                 
  path = "/heartbeat"                                                                                                                                                                                                                          
  port = "80"                                                                                                                                                                                                                                  
  healthy_threshold = 3                                                                                                                                                                                                                        
  unhealthy_threshold = 3                                                                                                                                                                                                                      
  timeout = 5                                                                                                                                                                                                                                  
  interval = 50                                                                                                                                                                                                                                
  protocol = "HTTPS"
  matcher = "200"                                                                                                                                                                                                                            

}
}

resource “aws_autoscaling_attachment” “test” {
autoscaling_group_name = “${aws_autoscaling_group_auto_scale.id}”
alb_target_group_arn = “${aws_alb_target_group.test.arn}”
}

Regards.