I'm not sure when it appears, but I know that I already used your module in a previous project with success, and the same code with another project no longer work, so I suppose that there were an update in omnipay itself.
Here is the error I get when I try to call the completePurchase() method :
Symfony\Component\Debug\Exception\FatalErrorException: Class Omnipay\SystemPay\Message\CompletePurchaseRequest contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (Omnipay\SystemPay\Message\AbstractRequest::getEndpoint) in /httpdocs/vendor/hounddd/omnipay-systempay/src/Message/CompletePurchaseRequest.php:10
So, as suggested by the debug, I implemented the getEndPoint() method in this PR for the CompletePurchaseRequest class and everything works again.
I'm not sure when it appears, but I know that I already used your module in a previous project with success, and the same code with another project no longer work, so I suppose that there were an update in omnipay itself.
Here is the error I get when I try to call the completePurchase() method :
So, as suggested by the debug, I implemented the getEndPoint() method in this PR for the CompletePurchaseRequest class and everything works again.