Changin the charset of application Laravel

I have a laravel app connected to a firebird DB the charset of the DB is

WIN1251 i set this in my .env like:

DB_CHARSET=WIN1251

but when i try to get data using #query_builder :

$product = DB::table('products')
    ->where('id', '=', 34)
    ->pluck(
        'name'
    );

I have an exception like:

Malformed UTF-8 characters, possibly incorrectly encoded

via Chebli Mohamed