How to call wordpress menu inside custom codeblock inside 3rd party builder?

Hi,

I am using WordPress with the addition of the oxygen builder. I build a language switch menu inside the normal wordpress menu creation but I can't find a way to include this menu inside a codeblock inside my oxygen builder. I have the ability to add a codeblock with html/php, css and js code but where do I find informations how to call a wordpress menu inside a custom code block?

Thanks for your help!