I'm reading the documentation about alb, and what confusing me is the line of code

security_groups=[aws_security_group["lb_sg"]["id"]],

I believe the documentation assumed that I already have created a security group for application load balancer. But what if I want to create a new security group for alb? You have a documentation on how to create security group on elb but I think that alb has different approach in creating one.

Hi, we have examples on creating security groups here. In this case you would create the security group before creating the load balancer and then reference it as you have above