Hello Michael Mansour !

You need to complete 3 actions:

1) in the file inc/header.inc.php change the domain in the line like:

define('BX_DOL_URL_ROOT', 'host1.example.com '); ///< site url

2) go to this area https://una.io/page/my-sites and generate the new key-secret pair for host2.example.com and set this data in Studio->Settings->General area.

3) clear all content from the cache and cache public folders (leave there only .htaccess files).