Random order on store-list page

functions.php

<?php

function dokan_store_listing_orderby_ramdom_filter( $seller_args ) {
    $seller_args['orderby'] = 'dokan_store_rand';
    return $seller_args;
}
add_filter( 'dokan_seller_listing_args', 'dokan_store_listing_orderby_ramdom_filter', 99 );
function dokan_store_listing_orderby_filter_query( $query ) {
    if ( $query->query_vars['orderby'] === 'dokan_store_rand' ) {
        $order_by = [
            'ID',
            'user_login, ID',
            'user_email',
            'user_registered, ID',
            'user_nicename, ID'
        ];
        if ( false === ( $selected_orderby = get_transient( 'dokan_store_listing_random_orderby' ) ) ) {
            $selected_orderby = $order_by[ array_rand( $order_by, 1 ) ];
            set_transient( 'dokan_store_listing_random_orderby', $selected_orderby, MINUTE_IN_SECONDS * 10 );
        }
        $query->query_orderby = "ORDER BY $selected_orderby";
    }
}
add_action( 'pre_user_query' , 'dokan_store_listing_orderby_filter_query' );

I received a critical error when I added this to my child theme! What should I do?