To configure Google reCAPTCHA you need to register your website at Visit Google reCAPTCHA Site and get public and private keys for your website after successful registration.
Please note that you must add the URL of YOUR website and select reCAPTCHA V2 correctly otherwise the reCAPTCHA won't work.
After that use those keys to fill the related fields in Easy Real Estate → Settings → reCAPTCHA as displayed below.
If you are running the Real Homes theme older than 3.9.0 version then related settings can be found by navigating to Dashboard → Real Homes → Customize Settings → Google reCAPTCHA
Once reCAPTCHA keys are configured, Google reCAPTCHA will be activated on all forms throughout the Real Homes theme.