API Create Multiple Input Laravel - mysql

Question

I'm currently creating API for multiple inputs using laravel. The data will be stored into two tables : Order and Detail_Order. One order can have many detail orders.
But now, the data only stored into Order table, and got an error: ErrorException: Invalid argument supplied for foreach() in file. Does anyone know how? Thank you.
Here's my code :
public function createDetail($total_passenger, $id_trip, $id_users, Request $request){
$trip = Trip::where(['id_trip' => $id_trip])->get();
$seat = $request->id_seat;
if(Detail_Order::where(['id_trip' => $id_trip, 'id_seat' => $seat])
->where('status', '!=', 5)
->exists()) {
return $this->error("Seat has been booked");
}else{
$order = new Order();
$order_select = Order::select('id_order');
$order_count = $order_select->count();
if ($order_count === 0) {
$order->id_order = 'P1';
}else{
$lastrow=$order_select->orderBy('created_at','desc')->first();
$lastrow_id = explode('P', $lastrow->id_order);
$new_id = $lastrow_id[1]+1;
$order->id_order = 'P'.$new_id;
}
$order->id_trip = $id_trip;
$order->id_users = $id_users;
$order->date_order = date('Y-m-d H:i:s');
$order->id_users_operator = 'O4';
$order->save();
foreach($request->passenger_name as $key => $value){
Detail_Order::create([
'id_trip' => $order->id_trip,
'id_seat' => $request->id_seat[$key],
'id_order' => $order->id_order,
'passenger_name' => $request->passenger_name[$key],
'gender' => $request->gender[$key],
'departure' => $request->departure[$key],
'destination' => $request->destination[$key],
'phone' => $request->phone[$key],
'status' => 1
]);
}
return response()->json([
'status' => true,
'message' => "Successfully saved data",
'data' => $order
]);
}