Thank you for your answer.
But I don’t understand how I can retrieve the order or checkout from the post-purchase extension, as I don’t have access to the order id or checkout token in the Checkout::PostPurchase::Render and Checkout::PostPurchase::ShouldRender extension points.
I have access to the purchase reference id in inputData.initialPurchase but it seems useless to retrieve the corresponding order or checkout, isn’t it?
(I specify that I do not store the orders on my side)
Simon