Hi
I have setup the sandbox for PayPalExpress and I have tested with this link and it look like is working fine.
https://api.sandbox.paypal.com/nvp?U...nsactionSearch
When I test this in the web site I get this error
Error: [10002] Security header is not valid
Are there any other setting to be changed including url links to the sandbox
I wonder if someone else has find the same problem and would help me.
Thank you![]()