- Follow standard instruction at https://www.phpbb.com/extensions/installing/
- copy 'cleantalk' folder with all subfolders int your 'ext' directory.
- enable 'CleanTalk. Spam protection' extension.
- Get access key at https://cleantalk.org/install/phpbb3?step=2
- Go to this extension settings page and save access key and needed antispam options.
- Stops spam bots signups.
- Stops spam bots posts.
- Allow guests posting without CAPTCHA.
Yours, CleanTalk.