reCAPTCHA registration not accepted on my website?

Hello,

I've registered more than once for API keys since when I want to use a
certain plugin on my website I get this message on the page where I insert
the plugin shortcode:

To use reCAPTCHA you must get an API key from
https://www.google.com/recaptcha/admin/create

Even though I have the keys, the website still doesn't display that page. I
keep getting the same message.

What can I do?

Thanks