Question New install Plesk on Ubuntu 22.01 configuration

[Nilbud]

Server operating system version

ubuntu 20.04

Plesk version and microupdate number

Plesk Obsidian v18.0.50

I just set up a new Ubuntu 22.04 server with the latest (50) Plesk. I use cloudflare as my DNS proxy. I know that the IP's from cloudflare will get blocked soon. I want to set the system up to allow cloudflare and block everyone else. So what I want to know is given I'm using fail2ban and modsecurity and apache2 and nginx and iptables and all that what is the cleanest least intrusive way to make this work.