Thanks for pointing that out @joda. The seller does get a private message from a npub generated by Shopstr with your cashu tokens as payment as well as who and what this purchase is for.
As of right now the buyer doesn't get any confirmation from Shopstr but you can perhaps send a DM to the seller for them to confirm receipt of the payment.
We are working on sending the buyer a notification as well and am still playing with some ideas on what the best way for buyers/sellers to be able to track their purchases is.
Thanks for taking the time to test it and write feedback! We really value and appreciate these conversations!