Error in gitlab-ci when trying to use hashicorp/dir/template module

Question

I'm getting the error that base_dir is an invalid argument. But according to the documentation on the hashicorp repo, it's a required string.

Here's my main.tf:

terraform {
  backend "http" {}
  required_providers {
    gitlab = {
      source  = "gitlabhq/gitlab"
      version = "~> 3.1"
    }
    aws = {
      source  = "hashicorp/aws"
      version = "~> 3.27"
    }
  }
  required_version = ">= 0.14.9"
}

module "template_files" {
  source   = "hashicorp/dir/template"
  base_dir = "${path.module}/../frontend"
}

Any ideas as to why gitlab would not be able to see the module properly? I'm just trying to get my files into the s3 bucket, but I can't even get a plan to run yet. Thanks in advance!