Answers for "laravel changing primary key"

laravel model string primary key

class UserVerification extends Model
{
    protected $primaryKey = 'your_key_name'; // or null

    public $incrementing = false;

    // In Laravel 6.0+ make sure to also set $keyType
    protected $keyType = 'string';
}

laravel migration with primary key

$table->string('code', 30)->primary();