Stripe PHP Redirect to Checkout.js: Free Trial Subscriptions + One-Time Fee (Client-Side Flow)

stripe_free-trial-checkout.php

$stripe->checkout->sessions->create([
  'success_url' => 'https://example.com/success',
  'cancel_url' => 'https://example.com/cancel',
  'payment_method_types' => ['card'],
  'line_items' => [
    [
      'price' => 'price_recurring',
      'quantity' => 1,
    ],
    [
      'price' => 'price_one_time',
      'quantity' => 1,
    ],
  ],
  'mode' => 'subscription',
  'subscription_data' => [
    'trial_period_days' => 14, 
  ], 
]);