What are these fields at the PayPal Website Payment Pro configuration page:
1. API Username
2. API Password
3. Security Certificate
and how do I get this information from my PayPal account?
1. Log into your PayPal account.
2. Click on the "My PayPal" link at the top right.
3. Click 'Tools -> All Tools'.
4. Scroll down a bit, click on the "API credentials" box.
5. In the first section "Pre-built payment solution", click on the "Add or edit API permissions" link.
6. In the "Option 2" box on the right side, click on the "Request API credentials" link.
7. On the right hand-side box, click on the "Request API certificate if your shopping cart or solution provider requires a file-based certificate." option.
8. Click the "Agree and Submit" button.
9. The "Manage API certificate" page loads. Copy your "API username" and "API password" from this page.
10. Click to "Download certificate".
11. Save the certificate to your computer.
12. Update your API Username and API Password at the Payment settings page at your store admin panel.
13. Upload the Security certificate you downloaded in #10.