How to retrieve initial root credentials for Elasticsearch?

When you create an Elasticsearch instance using azurerm_elastic_cloud_elasticsearch, how do you retrieve the initial root credentials of the instance?

When you create the instance using the ec_deployment resource in the ec Elastic Cloud Provider from Elastic, you can retrieve the credentials through the elasticsearch_username and elasticsearch_password attributes, cf. Terraform Registry.

But this will not work when you create the instance using azurerm_elastic_cloud_elasticsearch, because elasticsearch_username and elasticsearch_password are not present in the ec_deployment data source. The following code will not work:

resource "azurerm_elastic_cloud_elasticsearch" "default" {
  name                        = "${var.projectName}-elasticsearch"
  resource_group_name         = azurerm_resource_group.default.name
  location                    = azurerm_resource_group.default.location
  sku_name                    = "ess-monthly-consumption_Monthly"
  elastic_cloud_email_address = "THES@softwareag.com"

  logs {
    send_activity_logs = true
    send_azuread_logs = true
    send_subscription_logs = true
  }

  tags = {
    environment = "${var.projectName}"
  }
}

provider "ec" {
    apikey = "XXX"
}

data "ec_deployment" "default" {
  id = azurerm_elastic_cloud_elasticsearch.default.elastic_cloud_deployment_id
}

output "elasticsearch_endpoint" {
  value = data.ec_deployment.default.elasticsearch[0].https_endpoint
}

output "elasticsearch_username" {
  value = data.ec_deployment.default.elasticsearch_username
}

output "elasticsearch_password" {
  value = data.ec_deployment.default.elasticsearch_password
  sensitive = true
}

Thanks for your help!

Best regards,
Thomas