I have created a PayPal sandbox account Credit Card - Visa and linked this account to Braintree. In my application, when I am trying to pay using this sandbox account it is asking for IPIN/WEBPIN. Where can I get this IPIN from?
Full disclosure, I work at Braintree. If you have any further questions, please contact Support
Based on the URL, this is a production PayPal flow, not sandbox. If you meant do do sandbox testing, I recommend using a sandbox account. You can sign up for a sandbox account and begin testing. I recommend following Braintree's developer docs for PayPal for testing.
This looks like 3D Secure verification within PayPal. The card issuer associated with the card you are using is asking for the IPIN or WEB PIN associated with that card for verification, because it is a valid production card. If this is not your credit card, please do not use it in that production flow. If PayPal happened to generate that card for sandbox use, please only use it in the sandbox environment.