403 Authentication error when creating DNS records

When creating DNS records using Terraform, the API returns the following error:

Error: failed to create DNS record: HTTP status 403: Authentication error (10000)

This is caused by an error in your code syntax, when you are not using index [0] for the zones. Find an example below and a more detailed thread on GitHub ↗.

Instead of this:

zone_id = data.cloudflare_zones.example_com.id

Use this:

zone_id = data.cloudflare_zones.example_com.zones[0].id`