How to extract information from pg_ddl_command type

The function pg_event_trigger_ddl_commands() returns several columns, one of them being "command" that is of the type
"pg_ddl_command".
 

The manual[1] describes this column as: 

> A complete representation of the command, in internal format. 
> This cannot be output directly, but it can be passed to other 
> functions to obtain different pieces of information about the 
> command.

However, I can not find any of those "other functions" to extract information from that column. 

My goal is to get the complete SQL text that fired the event trigger - is that even possible through
pg_event_trigger_ddl_commands()?
 

Thanks
Thomas

[1] https://www.postgresql.org/docs/current/functions-event-triggers.html