[FIX] payment_paypal: include Build Notation reference

closes odoo/odoo#39772

Signed-off-by: Damien Bouvy (dbo) <dbo@odoo.com>

addons/payment_paypal/tests/test_paypal.py

@@ -55,6 +55,7 @@ class PaypalForm(PaypalCommon):
             'first_name': 'Norbert',
             'last_name': 'Buyer',
             'amount': '0.01',
+            'bn': 'OdooInc_SP',
             'currency_code': 'EUR',
             'address1': 'Huge Street 2/543',
             'city': 'Sin City',

addons/payment_paypal/views/payment_paypal_templates.xml

@@ -6,6 +6,7 @@
                 <input type="hidden" name="data_set" t-att-data-action-url="tx_url" data-remove-me=""/>
                 <input type="hidden" name="cmd" t-att-value="cmd"/>
                 <input type="hidden" name="business" t-att-value="business"/>
+                <input type="hidden" name="bn" value="OdooInc_SP" />
                 <input type="hidden" name="item_name" t-att-value="item_name"/>
                 <input type="hidden" name="item_number" t-att-value="item_number"/>
                 <input type="hidden" name="amount" t-att-value="amount"/>