Hi Prubi,

Is it EAP110 or EAP110-outdoor? I guess it is EAP110-Outdoor. How many EAP110-Outdoor do you have? If you have only one, you need to configure it via its Web UI.
So please directly read page 28 to page 36 of this document. http://static.tp-link.com/1910012212_EAP_UG.pdf

If you manage the EAP in standalone mode via its webpage, it supports three captive portal: No Authentication、Simple password and External Radius Server;
While if you manage the EAP via EAP controller, it supports five captive portal: No Authentication、Simple password、External Radius Server、hotspot and external portal server;

If you want to build or simply make a captive portal with no authentication, just read the terms of use and log it in, you can just choose 'No Authentication' mode.
You can use this portal in both standalone mode and EAP controller, It's not hard for configuration and you just need to enable it via webpage or EAP controller, you can modify its portal page and don't need to use a server with a domain.

Refer to FAQ http://www.tp-link.com/en/faq-896.html, if you use EAP controller for management.