sitekey error present on standard Netlify form

Question

I've added the data-netlify-recaptcha tag to my form and created an empty div with the same tags in my Netlify form and I keep seeing this error: "netlify Missing required parameters: sitekey".

I'm using the basic reCAPTCHA 2 challenge instructions from Netlify and I'm not adding a custom one so why is this error popping up?

heres the form:

<form
 name="contact-form"
 method="POST"
 data-netlify="true"
 netlify-honeypot="bot-field"
 data-netlify-recaptcha="true"
>
...
<div data-netlify-recaptcha="true"></div>
</form>

Any help would be appreciated.

Thanks.