Freemius

To work, the Blocklist Network Service must know:

• which sites are running the blocklist add-on,
• which version is in use,
• and a shared secret for secure communication.

Freemius already provides all these, and WP fail2ban already uses Freemius; why reinvent the wheel?

Therefore, unlike the core WP fail2ban plugin, you must opt into Freemius for the blocklist to work.