If you want to set dynamic home and siteurl in WordPress? You can override the admin settings in the wp-config.php file. So if you want something dynamic, the following should work:
define('WP_SITEURL', 'http://' . $_SERVER['HTTP_HOST']);
define('WP_HOME', 'http://' . $_SERVER['HTTP_HOST']);
This needs to added before the line
require_once(ABSPATH . 'wp-settings.php');
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