Eloquent insert id with sequence next value

php laravel laravel-5.3

PHP Snippet 1:

$billing->id = DB::getPdo()->lastInsertId(); // + 1 ?

PHP Snippet 2:

$nextval=DB::select(DB::raw("SELECT nextval('".(new Billing())->getTable()."_id_seq') as seq"))[0]->seq;

$billing = new Billing;

$billing->id = $nextval;
$billing->companyname = $request->companyname;
// ...

$billing->save();