Suddenly Google reCAPTCHA plugin in my wordpress site’s login page started displaying “Error for site owner: Invalid site key”. So i searched for the easy solution and luckily i got it. I hope it will work for you.
Step1: Follow the hyperlink to Register a new key.
Step 2: Click on Plus(+) symbol to create a new key.
Step 3: Fill the label, recaptcha type(you can choose v2/v3), domain name & owner. Then accept the reCAPTCHA Terms of Service and click on submit.
Step 4 : Now you can see the new site key and secret key .
Step 5 : Put the site key and secret key in the plugin settings .
Step 6: Now please check your page(Ex. login page) in which recaptcha is implemented.
I hope the article will help you. Please share your feedback in the comment section.