Error Creating Specific Docker Container in TF

cmennens@deb-1:~/terraform/postgres$ terraform -version
Terraform v1.1.4
on linux_amd64
+ provider v2.13.0

I am trying to learn terraform and I was using the official guide where they show you how to create a really quick and simple Nginx container using the following example:

terraform {
  required_providers {
    docker = {
      source  = "kreuzwerker/docker"
      version = "~> 2.13.0"

provider "docker" {}

resource "docker_image" "nginx" {
  name         = "nginx:latest"
  keep_locally = false

resource "docker_container" "nginx" {
  image = docker_image.nginx.latest
  name  = "tutorial"
  ports {
    internal = 80
    external = 8000

The above example works fine. Creates the container no problem.
When I attempt to deploy a postgres container using the the same example template above but changing every occurrence of “nginx” to “postgres”, it fails with:

│ Error: Unable to create container with image docker_image.postgres: unable to pull image docker_image.postgres: error pulling image docker_image.postgres: Error response from daemon: pull access denied for docker_image.postgres, repository does not exist or may require 'docker login': denied: requested access to the resource is denied
│   with docker_container.postgres,
│   on line 17, in resource "docker_container" "postgres":
│   17: resource "docker_container" "postgres" {