Tambahkan module league/csv

$ composer require league/csv

berikut contoh kodenya

<?php 
use Illuminate\Database\Seeder; 
use League\Csv\Reader; 

class DataCountrySeeder extends Seeder 
public function run() { 
$file = public_path().'/data/data_country.csv'; 
$csv = Reader::createFromPath($file);
$nbInsert = $csv->each(function ($row)  {
      if(empty($row)) return false;
        
      return  \DB::table('data_countries')->insert(
          array(
            'country_id' => $row[0],
            'country_name' => $row[1], 
          )
                  
        );
      });
    }
}