There are many scenarios in which you would want to expose a load balancer to the wider internet, but this check exists as a warning to prevent accidental exposure of internal assets. You should ensure that this resource should be exposed publicly.
The load balancer is exposed on the internet
Switch to an internal load balancer or add a tfsec ignore
The following example will fail the aws-elbv2-alb-not-public check.
The following example will pass the aws-elbv2-alb-not-public check.