I have a problem testing sandbox credit card on my PayPal Pro/Express Omnipay Gateway. I am using October CMS which runs on Laravel and as I understand it uses the Laravel plugins for PayPal payments.
Now the problem is that I have username, password and signature credentials, but I took them from my live PayPal account. Problem is that I can't find the same credentials on sandbox PayPal account. I found the credentials in this page: https://www.paypal.com/businessprofile/mytools/apiaccess/firstparty/signature
Now at the checkout process I get a response from PayPal which says:
"Security header is not valid"
As I understand I get this because I use live credentials on testing environment, but how can I get the sandbox credentials to test this?
Thank you.
PAYPAL credentials can be found under Sandbox -> Accounts -> Profile -> API Credentials.
Notice they might have to be url encoded ( http://www.php.net/urlencode ) before sending them.