I'm using Omnipay with PayPal, I am notified that the payment was successful. But I do not see the action in the dev paypal account https://developer.paypal.com/developer/notifications/
https://pastebin.com/gM4VsB0m
Could that be because you're giving it a return URL that can't possibly work for anyone but you? (Including, not working for THEM ... 😉 )