How to view auto generated cypher statements?

how to see generated cypher for graphql schema?
Using the neo4j-graphql-js library, it is apparently possible to log out the generated cypher statements with an environment variable:

DEBUG=neo4j-graphql-js node yourcode.js

Can someone explain to me how this works, and how I can 'run' the env variable to log out the statements?

If you're just curious as to what mutations are created it's a lot easier to see them in the Graphiql playground as you can see the parameters as well. Sorry, I know that's not a direct answer to your question.