Wagtail Grapples: error at url http://127.0.0.1:8000/graphql/

[paragliding-nsk]

Hello, may I ask for help: what I'm doing wrong?

After installing wagtail-grapple and opening url http://127.0.0.1:8000/graphql/ I have only white screen and message:
{"errors":[{"message":"Must provide query string."}]}

Is it possible to change it into something like this:

[zerolab]

/graphql is the API endpoint. if you want the graphical interface, use /graphiql

[paragliding-nsk]

Thanks a lot!

[VladimirLevadnij]

I want to add that the /graphiql link worked for me only after I added the line "EXPOSE_GRAPHIQL": True to the Wagtail Grapples configuration.