Are you trying to exclude a hostname (like sub.example.com) under your domain name (example.com) while using “I am under an attack mode!”, or rather someone else “host” (rather IP address?), so their requests are bypassed and allowed to access your Website despite “IUAM” mode being used and enabled?
Using Page Rules we can set Security Level to “off” to disable “IUAM” mode (if enabled for the whole domain)
“IUAM” mode should be used only in specific circumstances.