Terraform command is not using the values from the tfvars file provide with --var-file

I am pretty new in Terraform, trying to create separate backend for each AWS Region under each environment (dev, stg, prod) of my application. So, I am using separate .config files to configure separate backend, and separate .tfvars files to create resources on relevant environmet/regions.

I am detailing everything below:

Folder structure:

.
├── config
│   ├── stg-useast1.config
│   ├── stg-uswest2.config
│   ├── prod-useast1.config
│   └── prod-uswest2.config
├── vars
│   ├── stg-useast1.tfvars
│   ├── stg-uswest2.tfvars
│   ├── prod-useast1.tfvars
│   └── prod-useast1.tfvars
└── modules
    ├── backend.tf
    ├── main.tf
    ├── variables.tf
    └── module-ecs
        ├── main.tf
        └── variables.tf

File contents necessary for this question are showing below (just one region):

./config/stg-useast1.config

profile        = "myapp-stg"
region         = "us-east-1"
bucket         = "myapp-tfstate-stg-useast1"
key            = "myapp-stg-useast1.tfstate"
dynamodb_table = "myapp-tfstate-stg-useast1-lock"

./vars/stg-useast1.tfvars

environment = "stg"
app_name    = "myapp-ecs"
aws_region  = "us-east-1"
aws_profile = "myapp-stg"

./modules/backend.tf

terraform {
  backend "s3" {
  }
}

./modules/main.tf

provider "aws" {
  region                   = var.aws_region
  shared_credentials_files = ["~/.aws/credentials"]
  profile                  = var.aws_profile
}

module "aws-ecr" {
  source = "./ecs"
}

./modules/variables.tf

variable "app_name" {}
variable "environment" {}
variable "aws_region" {}
variable "aws_profile" {}

./modules/module-ecs/main.tf

resource "aws_ecr_repository" "aws-ecr" {
  name = "${var.app_name}-${var.environment}-ecr"
  tags = {
    Name        = "${var.app_name}-ecr"
    Environment = var.environment
  }
}

./modules/module-ecs/variables.tf

variable "app_name" {
    default = "myapp-ecs"
}
variable "environment" {
    default = "stg"
}
variable "aws_region" {
    default = "us-east-1"
}
variable "aws_profile" {
    default = "myapp-stg"
}

The terraform init went well.

$ terraform init --backend-config=../config/stg-useast1.config
Initializing modules...

Initializing the backend...

Initializing provider plugins...
- Reusing previous version of hashicorp/aws from the dependency lock file
- Using previously-installed hashicorp/aws v4.31.0

Terraform has been successfully initialized!

I ran terraform plan as following:

terraform plan --var-file=../vars/stg-useast1.tfvars

But it did not use the values from this .tfvars file. I had to supply them in ./modules/module-ecs/variables.tf as default = <value> for each variables.

How can I make use of the .tfvars file with terraform plan command?

Any restructuring suggestion is welcomed.

The local module you've created doesn't inherit variables. You will need to pass them in. For example:

module "aws-ecr" {
  source = "./ecs" # in your example it looks like the folder is ecs-module?
  app_name = var.app_name
  environment = var.environment
  aws_region = var.region
  aws_profile = var.profile
}