Add PayPal support for add-on and gift voucher checkout

tests/Feature/Api/GiftVoucherLookupTest.php

@@ -28,6 +28,25 @@ class GiftVoucherLookupTest extends TestCase
             ->assertJsonPath('data.currency', 'EUR');
     }
 
+    public function test_it_returns_voucher_by_paypal_order_id(): void
+    {
+        $voucher = GiftVoucher::factory()->create([
+            'code' => 'GIFT-PAYPAL',
+            'amount' => 59.00,
+            'currency' => 'EUR',
+            'paypal_order_id' => 'ORDER-PAYPAL-1',
+            'paypal_capture_id' => 'CAPTURE-PAYPAL-1',
+            'status' => GiftVoucher::STATUS_ISSUED,
+        ]);
+
+        $response = $this->getJson('/api/v1/marketing/gift-vouchers/lookup?order_id=CAPTURE-PAYPAL-1');
+
+        $response->assertOk()
+            ->assertJsonPath('data.code', $voucher->code)
+            ->assertJsonPath('data.amount', 59)
+            ->assertJsonPath('data.currency', 'EUR');
+    }
+
     public function test_it_returns_voucher_by_code(): void
     {
         $voucher = GiftVoucher::factory()->create([