Calling Metabase Environment Variables Directly Inside Query

On MySQL, you can directly call global variables in queries by using '@@' then followed by the variable name. Can we do the same in Metabase, but we're calling Metabase's environment variables instead?

nope, you can't do this right now. Please upvote the following issue: Using custom environment variables, on metabase SQL Query · Issue #6383 · metabase/metabase · GitHub