function plt_hide_wp_graphql_menus() {
//Hide "GraphQL".
remove_menu_page('graphiql-ide');
//Hide "GraphQL → GraphiQL IDE".
remove_submenu_page('graphiql-ide', 'graphiql-ide');
//Hide "GraphQL → Settings".
remove_submenu_page('graphiql-ide', 'graphql-settings');
//Hide "GraphQL → Extensions".
remove_submenu_page('graphiql-ide', 'wpgraphql-extensions');
}
add_action('admin_menu', 'plt_hide_wp_graphql_menus', 101);