Max--

[stoic mural]

It depends on how you use the Subscription. ie if you use Checkout, it will automatically determines the currency based on user IP Address. But if you use PaymentElement you would need to specify the currency on initialization

[azure laurel]

It is a subscription created in a current Customer that already paid for another product.

If I create the subscription like this example in the customer. Will it use the customer currency?

$createSub = $stripe->subscriptions->create( [ 'customer' => $customer_id, 'items' => [ ['price' => 'price_priceID'], ], 'trial_end' => $end_time, ] );