how to install recptcha

I have activello. I downloaded 'advanced no captcha & invisible captcha v.2 by shamin hasan on the word press Plug in page. I found the sitekey and secret key from google (that was difficult) . Put in the key codes in the 'settings" for ‘advanced nocaptcha etc’. We only want it on the ‘contact us’ page because we are getting constant spam requests on the contact page. nothing has worked. How do I instal it?? Help. I look online and at Google and I cant find a simple solution. Simple for me. thnx

Hi there

Sorry, you have to contact the plugin author about installation steps and instructions