Computed attributes cannot be set : org_id - terraform

Question

I am learning how to use Terraform. My aim is to deploy an architecture on GCP so here's my main.tf so far :
terraform {
required_providers {
google = {
source = "hashicorp/google"
version = "3.85.0"
}
}
}
provider "google" {
credentials = file(var.credentials_file)
region = var.region
zone = var.zone
}
data "google_organization" "org" {
domain = var.organization.display_name
org_id = var.organization.id
directory_customer_id = var.organization.directory_customer_id
}
resource "google_folder" "shared" {
display_name = "Shared"
parent = google_organization.org_id
}
resource "google_folder" "ddm" {
display_name = "Data and Digital Marketing"
parent = google_folder.shared.name
}
resource "google_folder" "dtl" {
display_name = "DTL"
parent = google_folder.ddm.name
}
According to the documentation, org_id is within the Attributes Reference
But I get the following errors:
╷
│ Error: Computed attributes cannot be set
│
│ with data.google_organization.org,
│ on main.tf line 17, in data "google_organization" "org":
│ 17: org_id = var.organization.id
│
│ Computed attributes cannot be set, but a value was set for "org_id".
╵
╷
│ Error: Computed attributes cannot be set
│
│ with data.google_organization.org,
│ on main.tf line 18, in data "google_organization" "org":
│ 18: directory_customer_id = var.organization.directory_customer_id
│
│ Computed attributes cannot be set, but a value was set for "directory_customer_id".
╵
╷
│ Error: Reference to undeclared resource
│
│ on main.tf line 22, in resource "google_folder" "shared":
│ 22: parent = google_organization.org_id
│
│ A managed resource "google_organization" "org_id" has not been declared in the root module.
What am I doing wrong?

Answer 1

The organization is set as a data source, but in the previous code, it is used like a resource block.
What needs to be done to reference the organization is this :
data "google_organization" "org" {
organization = var.organization.id
}
org_id is an output, not an input. The only acceptable inputs are organization ordomain; they are mutually exclusive.
And use its outputs like this :
resource "google_folder" "shared" {
display_name = "Shared"
parent = data.google_organization.org.org_id
}
EDIT : This, although syntactically correct, it might not work because the account used must be organization administrator on the organization level. I do not recomment using the google_organization data sourcejust to fetch the ID and other info, I ended up writing those in a variable and just calling it this way :
resource "google_folder" "shared" {
display_name = "Shared"
parent = "organizations/${var.organization.id}"
}