Flutter Graphql

#GraphQL Exception: OperationException(linkException: ServerException(originalException: null,
originalStackTrace: null, parsedResponse: Response(data: null, errors: [GraphQLError(message: Cannot query
field `screenCategories' on type `Query'., locations: [ErrorLocation(line: 3, column: 3)], path: null,
extensions: {field-name: screenCategories, type-name: Query})], context: Context({ResponseExtensions: Instance
of 'ResponseExtensions'}), response {errors: [{message: Cannot query field `screenCategories' on type `Query'.,
locations: [{line: 3, column: 3}], extensions: {field-name: screenCategories, type-name: Query}}]})),
graphqlErrors: [])