Lucas Bonomo

Just show the remote IP of client (with a shortcode [show-remote-ip]) and public an endpoint to show the IP (/wp-json/show-remote-ip/v1/get-ip)

Show Remote IP

Just show the remote IP of client (with a shortcode [show-remote-ip])  and public an endpoint to show the IP (/wp-json/show-remote-ip/v1/get-ip)

Masoud Binaei

This plugin allow WordPress to detect Real visitors IP Address when WordPress is behind of Reverse Proxy, Load Balancer or CDN. 
It will start working as soon as you activate it.
It is also compatible:
<ul>
<li>Cloudflare.com</li>
<li>geniusguard.com</li>
<li>central-hosting.com</li>
<li>incapsula.com</li>
<li>sucuri.net</li>
<li>barracuda.com</li>
<li>f5.com And Other…</li>
</ul>

Real IP Detector

Very good

This plugin allow WordPress to detect Real visitors IP Address.

Show Remote IP vs Real IP Detector