How To Test Paypal Express Using Sandbox Account

I implemented paypal express checkout using the following document

I tried to test it before going to live, so i get the sandbox testing accounts from paypal sandbox and put those credentials in configure tab(check the attached screen shot)

In checkout page when i choose the paypal payment method and click on "submit my order " button its again redirecting to the same checkout page not to the paypal website

After that i changed the configuration settings “Test/Live mode:” as Live and again i tried with the above process now its showing the following error
“Error 10002 Security error: Security header is not valid”

could you please help me how to test the paypal express using sandbox testing account

Anil kumar

paypal express payment integeration.png


The issue may occur if PayPal services do not accept HTTPS requests from your store.

First of all, please, make sure your server meets current PayPal security requirements.

You can find the "how-to" in this thread: