I bought the Komento plugin and it looked like everything was going great.
I created a new api key on my google account see attached, created last week now a new key created today.
Set the reCAPTCHA option in the Komento settings as per documentation.
Tried activating joomla reCAPTCHA plugin and then tried it without the joomla reCAPTCHA pugin?
So at a loss guys, tried looking for posting relating to reCAPTCHA but nothing. Unfortunately your documentation screen grabs are out of date but I submitted the api key in both the 'site key' field and the 'secret key' field as google only give a single key when generating a key.
Need to get this running for my client asap. I'll raise a seperate ticket for the notification not working.