Invoice PAIN & CSV can be uploaded

app/Models/Invoice.php

@@ -80,4 +80,8 @@ class Invoice extends InstancedModel
     public function invoiceType() : InvoiceType {
         return $this->belongsTo(InvoiceType::class, 'type', 'slug')->first();
     }
+
+    public function approvedBy() : ?User {
+        return $this->belongsTo(User::class, 'approved_by')->first();
+    }
 }