Where can I enable debug messages?

Hi,

how can I use the following code snippet? 

<#if utils.logs.name.common_init.debugEnabled>
     ${utils.logs.name.common_init.debug("my debug message")}
</#if>

I implemented it to debug something within the page initialization but I don't see any change at all after updating the stage environment. Where can I enable the debug messages?

https://freemarker-docs-portal.lithium.com/refer/contextObjects#utilsForLogging

Thanks in advance

micha80