Providing list of string values in terraform apply command using "-var" option

I am trying to run this command .
terraform apply -var ‘aws_azs=[“us-east-2c”, “us-east-2b”]’

It is failing with this error -
Error: Invalid value for module argument

on main.tf line 20, in module “mgmt-server-vpc”:
20: azs = “${var.aws_azs}”

The given value is not suitable for child module variable “azs” defined at
.terraform/modules/mgmt-server-vpc/terraform-aws-modules-terraform-aws-vpc-13fc020/variables.tf:241,1-15:
list of string required

Any idea how to fix it?

This isn’t really an answer to your question, but why not define it in a file and reference the file with -var-file=(filename).