only getalluser demo worked, others show "got an unexpected keyword argument 'xxxx'"

[mariuswang007]

only getalluser worked for me. others always show error: "got an unexpected keyword argument 'xxxxx'"
anyone has the same issue ?
e.g：
{ findUser(username: "xxx") { id, name, email } }

{ "errors": [ { "message": "resolve_find_user() got an unexpected keyword argument 'username'", "locations": [ { "line": 2, "column": 3 } ], "path": [ "findUser" ] } ], "data": { "findUser": null } }