How do the keys work with reCAPTCHA v3 Enterprise?

I'm trying to include reCAPTCHA in a React application I'm developing, with Next.js for the server side functionality.

I think I'm fundamentally confused by reCAPTCHA Enterprise.

The former "free" way to register a domain with reCAPTCHA was such that users were given a public reCAPTCHA key, and a private reCAPTCHA key for the backend. That's from using Google's reCAPTCHA v3 as registered via "Admin" at https://www.google.com/recaptcha/admin/create.

Given I have a GCP account, I'm redirected to the reCAPTCHA Enterprise API. Here there is only one key available. Is there no secret key for use in reCAPTCHA Enterprise?

If so, how does one use this? Is there no private key anymore?

For the Secret key / Back-end Authentication, you will need to create that together with the Service Account.

1. Create a Service Account
2. Select the Role reCAPTCHA Enterprise Agent
3. Click the email address for the service account that you created
4. Add key, select JSON and click Create
5. Click Close

For a more detailed steps, check the official documentation here.

I would also recommend reading the quick start page on the reCAPTCHA Enterprise official documentation. It will provide you information what is the best method for your use case and also the keys that is appropriate for your application.