Schema is not configured for mutations in webonyx/graphql-php - php

Question

i'm new in graphql.
I'm try to config graphql mutation via siler+swoole php framework, that use webonyx/graphql-php.
When i post query i'm get error "Schema is not configured for mutations", but it's configured in my shema.
My index
$typeDefs = file_get_contents(__DIR__.'/schema.graphql');
$resolvers = include __DIR__.'/resolvers.php';
$schema = GraphQL\schema($typeDefs, $resolvers);
GraphQL\execute($schema, GraphQL\request()->toArray(), [], [])
schema.graphql :
schema {
query: Query
mutation: Mutation
}
type Query {
clusters: [Cluster!]!
}
type Cluster {
id: Int
title: String
}
type Mutation {
addCluster(title: String!): Cluster!
}
resolver.php
<?php
use RedBeanPHP\R;
//R::setup('sqlite:'.__DIR__.'/db.sqlite');
$clusters = [
'clusters' => function () {
return R::findAll('clusters');
},
];
$queryType = [
'clusters' => function () {
return R::findAll('clusters');
},
];
$mutationType = [
'addCluter' => function ($root, $args) {
$title = $args['title'];
$cluster = R::dispense('cluster');
$cluster['title'] = $title;
R::store($cluster);
return $cluster;
},
];
return [
'Cluster' => $clusters,
'Query' => $queryType,
'Mutation' => $mutationType,
];
And my query is:
mutation addCluster($clusterName: String) {
addCluster(clusterName: $clusterName) {
id
}
}
The response says:
Schema is not configured for mutations