Do mutations work in dgraph?

Hi, I am trying out dgraph and passing through some initial examples and I am trying a simple mutation after following out these steps at

and I get this error
Message: while lexing mutation { addUser(input: [ { username: “[email protected]”, name: “Alice”, tasks: [ { title: “Avoid touching your face”, completed: false, }, { title: “Stay safe”, completed: false }, { title: “Avoid crowd”, completed: true, }, { title: “Wash your hands often”, completed: true } ] } ]) { user { username name tasks { id title } } } } at line 1 column 0: Invalid block: [mutation]

Did you execute it in ratel? This is a GraphQL statement that should be executed in the GraphQL client.