Вот несколько способов реализации ежемесячной подписки VPN на примерах кода:

1. Интеграция Stripe API:
   Вы можете использовать Stripe API для обработки платежей по подписке и управления подписками пользователей. Вот пример использования библиотеки Stripe Python:

import stripe
stripe.api_key = 'YOUR_STRIPE_SECRET_KEY'
def create_subscription(customer_id, plan_id):
    subscription = stripe.Subscription.create(
        customer=customer_id,
        items=[{'plan': plan_id}],
        billing='charge_automatically',
        expand=['latest_invoice.payment_intent'],
    )
    return subscription
# Usage
customer_id = 'CUSTOMER_ID'
plan_id = 'MONTHLY_PLAN_ID'
subscription = create_subscription(customer_id, plan_id)

2. Интеграция подписок PayPal.
   Если вы предпочитаете использовать PayPal для оплаты подписки, вы можете интегрировать их API. Вот пример использования REST API PayPal в Node.js:

const paypal = require('paypal-rest-sdk');
paypal.configure({
  mode: 'sandbox', // Change to 'live' for production
  client_id: 'YOUR_CLIENT_ID',
  client_secret: 'YOUR_CLIENT_SECRET',
});
function createSubscription(planId, userId) {
  const billingPlanAttributes = {
    description: 'Monthly VPN Subscription',
    name: 'Monthly Plan',
    type: 'INFINITE',
    payment_definitions: [
      {
        name: 'Regular Payment',
        type: 'REGULAR',
        frequency: 'MONTH',
        frequency_interval: '1',
        amount: {
          currency: 'USD',
          value: '9.99',
        },
        cycles: '0',
        charge_models: [
          {
            type: 'SHIPPING',
            amount: {
              currency: 'USD',
              value: '0',
            },
          },
        ],
      },
    ],
    merchant_preferences: {
      setup_fee: {
        currency: 'USD',
        value: '0',
      },
      return_url: 'https://yourwebsite.com/success',
      cancel_url: 'https://yourwebsite.com/cancel',
      auto_bill_amount: 'YES',
      initial_fail_amount_action: 'CONTINUE',
      max_fail_attempts: '3',
    },
  };
  paypal.billingPlan.create(billingPlanAttributes, (error, billingPlan) => {
    if (error) {
      console.error(error);
      return;
    }
    const billingAgreementAttributes = {
      name: 'Monthly VPN Subscription',
      description: 'Monthly VPN Subscription',
      start_date: new Date().toISOString(),
      plan: {
        id: billingPlan.id,
      },
      payer: {
        payment_method: 'paypal',
      },
      shipping_address: {
        line1: '1234 Main St',
        city: 'San Jose',
        state: 'CA',
        postal_code: '95131',
        country_code: 'US',
      },
    };
    paypal.billingAgreement.create(billingAgreementAttributes, (error, billingAgreement) => {
      if (error) {
        console.error(error);
        return;
      }
      const approvalUrl = billingAgreement.links.find(link => link.rel === 'approval_url').href;
      // Redirect the user to the approvalUrl to complete the subscription
    });
  });
}
// Usage
const planId = 'YOUR_PLAN_ID';
const userId = 'YOUR_USER_ID';
createSubscription(planId, userId);

3. Индивидуальное управление подпиской.
   Если вы предпочитаете самостоятельно управлять подпиской и обработкой платежей, вы можете реализовать индивидуальное решение, используя веб-инфраструктуру и платежный шлюз. Вот пример использования веб-фреймворка Django и платежного шлюза Braintree:

# views.py
from django.shortcuts import render
from django.conf import settings
from braintree import BraintreeGateway
gateway = BraintreeGateway(
    braintree.Configuration(
        environment=settings.BRAINTREE_ENVIRONMENT,
        merchant_id=settings.BRAINTREE_MERCHANT_ID,
        public_key=settings.BRAINTREE_PUBLIC_KEY,
        private_key=settings.BRAINTREE_PRIVATE_KEY,
    )
)
def create_subscription(request):
    client_token = gateway.client_token.generate()
    return render(request, 'subscription.html', {'client_token': client_token})
def process_subscription(request):
    nonce = request.POST['payment_method_nonce']
    result = gateway.transaction.sale({
        "amount": "9.99",
        "payment_method_nonce": nonce,
        "options": {
            "submit_for_settlement": True
        }
    })
    if result.is_success:
        # Subscription created successfully
        return render(request, 'success.html')
    else:
        # Subscription creation failed
        return render(request, 'error.html')
# subscription.html
<form action="{% url 'process_subscription' %}" method="post">
  <script src="https://js.braintreegateway.com/web/dropin/1.26.1/js/dropin.min.js"></script>
  <div id="dropin-container"></div>
 <script>
    var client_token = "{{ client_token }}";
    braintree.dropin.create({
        authorization: client_token,
        container: '#dropin-container'
    });
</script>
  <input type="submit" value="Subscribe">
</form>
# urls.py
from django.urls import path
from . import views
urlpatterns = [
    path('subscription/', views.create_subscription, name='create_subscription'),
    path('process_subscription/', views.process_subscription, name='process_subscription'),
]