serve/app/admin/library/crud/stubs/mixins/model/getters/remoteSelectLabels.stub

    public function get{%field%}Attr($value, $row): array
    {
        return [
            '{%labelFieldName%}' => {%className%}::whereIn('{%primaryKey%}', $row['{%foreignKey%}'])->column('{%labelFieldName%}'),
        ];
    }