Disable "enabled" field on PayPal payment method

src/Form/Extension/PaymentMethodTypeExtension.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sylius\PayPalPlugin\Form\Extension;
+
+use Sylius\Bundle\PaymentBundle\Form\Type\PaymentMethodType;
+use Sylius\Component\Core\Model\PaymentMethodInterface;
+use Symfony\Component\Form\AbstractTypeExtension;
+use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\Form\FormEvent;
+use Symfony\Component\Form\FormEvents;
+
+final class PaymentMethodTypeExtension extends AbstractTypeExtension
+{
+    public function buildForm(FormBuilderInterface $builder, array $options)
+    {
+        $builder->addEventListener(FormEvents::PRE_SET_DATA, function(FormEvent $event): void {
+            /** @var PaymentMethodInterface $data */
+            $data = $event->getData();
+            $form = $event->getForm();
+
+            if ($data->getGatewayConfig()->getFactoryName() === 'sylius.pay_pal') {
+                $form->add('enabled', CheckboxType::class, [
+                    'required' => false,
+                    'disabled' => true,
+                    'label' => 'sylius.form.payment_method.enabled',
+                ]);
+            }
+        });
+    }
+
+    public function getExtendedTypes(): iterable
+    {
+        return [PaymentMethodType::class];
+    }
+}

src/Resources/config/services.xml

@@ -14,6 +14,10 @@
     </parameters>
 
     <services>
+        <service id="Sylius\PayPalPlugin\Form\Extension\PaymentMethodTypeExtension">
+            <tag name="form.type_extension" extended-type="Sylius\Bundle\PaymentBundle\Form\Type\PaymentMethodType" />
+        </service>
+
         <service id="Sylius\PayPalPlugin\Form\Type\PayPalConfigurationType">
             <tag name="sylius.gateway_configuration_type" type="sylius.pay_pal" label="sylius.pay_pal.label" />
         </service>