codigo actual del servidor, con avances de joan

app/Models/CustomersImport.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace App\Models;
+
+use App\Models\Customer;
+use Maatwebsite\Excel\Concerns\ToModel;
+use Maatwebsite\Excel\Concerns\WithHeadingRow;
+use Illuminate\Support\Facades\Hash;
+
+class CustomersImport implements ToModel, WithHeadingRow
+{
+    public function model(array $row)
+    {
+        return new Customer([
+           'user_id'     => $row['user_id'],
+        ]);
+    }
+}