amount update

app/Models/User.php

@@ -94,6 +94,19 @@ public function invoices()
     return $this->hasMany(\App\Models\Invoice::class, 'customer_id', 'id');
 }
 
+// App\Models\User.php
+
+
+public function invoiceInstallments()
+{
+    return $this->hasManyThrough(
+        InvoiceInstallment::class,
+        Invoice::class,
+        'customer_id',   // FK on invoices
+        'invoice_id'     // FK on installments
+    );
+}
+
 
 
 }