Groub By Article Title

i try to get articles, and some articles have dublicated title i want to groub by title

        $articles=Article::select(
            'id',
            'img',
            'created_at',
            'title_ar',
        )->groupBy('title_ar')->limit(6)->get();

but i got this error

SQLSTATE[42000]: Syntax error or access violation: 1055 Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'mhpss.articles.id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by (SQL: select `id`, `img`, `created_at`, `title_ar` from `articles` group by `title_ar` limit 6)