Is it possible to use a standalone webapp as return url?

I am using a webapp for my webshop which can be saved (downloaded) to home screen, after which you can launch it is as a standalone webapp. I am using js xhr to navigate and submit.

The problem arises during checkout. When i press cancel on the payment screen i am navigated back to my site (not webapp) which starts a new session and the customer gets confused because the cart is empty.

Is it possible to return to a webapp using a special url or some other possibility?

• The payment screen is offered by third parties and includes a bank app.

• Adding the order data in the return url (not always possible) and using webhooks (too long) are not user friendly in this case. Loading the payment screen in a frame would be ideal but not allowed due to safety reasons.