work in InvoiceService

InvoiceService.php

<?php

namespace App\Acme\Services;

use App\Acme\Models\Invoice;
use App\Acme\Models\InvoiceItem;
use App\Acme\Models\Product;
use App\Acme\Models\User;
use App\Acme\Resources\InvoiceResource;
use App\Acme\Resources\UserResource;
use App\Acme\Traits\ApiResponseTrait;

class InvoiceService
{
    public function getInvoices()
    {
        $invoices = Invoice::with(['customer', 'items'])->orderBy('created_at', 'desc')->get();
        return InvoiceResource::collection($invoices);
    }

    public function newInvoice()
    {
        $customers = User::whereHas('roles', function ($query) {
            $query->where('name', 'like', 'customer%');
        })
            ->has('products')
          //  ->doesntHave('invoices')
            ->get();

        $customers->load('products');

        foreach ($customers as $customer) {
           
            foreach ($customer->products as $product) {
                  $invoiceItems = [
                    'name'       => $product->name,
                    'unit_price' => $product->pivot->custom_price,
                    'qty'        => $product->pivot->quantity
                  ];
            }

             $invoice = [
                    'user_id'      => $customer->id,
                    'due_date'     => '2019-12-5',
                    'sub_total'    => $product->pivot->custom_price * $product->pivot->quantity,
                    'type_payment' => $customer->type_payment,
                    'discount'     => $product->pivot->discount,
                    'total'        => $product->pivot->custom_price * $product->pivot->quantity - $product->pivot->discount,
              
                ];

        }
        
        $invoice = Invoice::create($invoice);
        $invoiceItem = $invoice->items()->create($invoiceItems);

        return new InvoiceResource($invoice);
    }

    public function deleteInvoice(Invoice $invoice)
    {
        $invoice->delete();
        return '';
    }
}

foreach ($customers as $customer) {
            
            foreach ($customer->products as $product) {
                 // criar dados dos produtos aqui                    
            }

             // Criar dados da invoice aqui

             // Criar a invoice Invoice::create($invoice);

            // Criar items para invoice $invoice->items()->create($invoiceItems);
        }