protect form with google recapcha

I wanted to protect my form with google recapcha .... I installed the "rsm_googlerecaptcha_modul" exentsion and updated the security question in in my form.
But I can't find the position to enter the keys!

Which menu, which submenu, where to click?


From the form error message:
Please set a website key and a private key at the root page of your website.

And the Extension description says:
hen enter these two keys at the website root of your website in the Contao side structure.


Many thanks
eactor