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Never add your server's IP address or an internal network IP address to the whitelist in cases like this. You would be effectively disabling all Admin Tools' protection.

Go to Joomla's Global Configuration and set "Behind Load Balancer" to Yes. Click on Save & Close to apply this setting.

These instructions are also in our documentation under the "Admin Tools' Web Application Firewall (WAF) locked you out of your site" section of the troubleshooting pages, and I have explained the what and why in a number of public tickets, e.g. https://www.akeeba.com/support/admin-tools/41162-admin-tools-with-bunnycdn.html#p223270 and https://www.akeeba.com/support/admin-tools/41898-cloudfare-1.html#p227205.

Note that if changing the setting in Joomla does not result in your site seeing a different IP address (check the exclusive IP allow page; it tells you which IP PHP sees for the current visitor i.e. you) you will have to ask your host to make sure that their reverse proxy / load balancer sets the X-Forwarded-For HTTP header. That's a de facto Internet standard, see https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-For.

If your host confirms that all your traffic goes through a reverse proxy, you should also go to the .htaccess Maker and set "Restrict access by IP" to Custom List, then enter the IP addresses of your host's reverse proxies as entries. Then, click on Save & Create .htaccess. This addresses the what you see on the MDN link above under "Security and privacy concerns" by preventing direct access to your site (as this would allow an attacker to pass a maliciously crafted X-Forwarded-For header which would obfuscate their identity during their attack, evading Admin Tools' automatic iP blocking).