To use PayPal Express Checkout, you will need to sign up for a PayPal business account and provide an API username and password, as well as a signature. Here’s how to obtain this information:

  1. Log into your PayPal Business account.
  2. Click Profile.
  3. Under the Account Information list, click API Access.
  4. Select the Request API Credentials option.
  5. Select Request API Signature.
  6. Click Agree and Submit.
  7. Copy your API account username. You can do this quickly by highlighting it with your mouse and using the keyboard shortcut Ctrl+C.
  8. Click Done.
  9. Click Grant API Permission.
  10. Enter your API account username in the appropriate field. You can do this quickly by clicking in the field and using the keyboard shortcut Ctrl+V.
  11. Select all four boxes.
  12. Click Submit.
  13. Click Give Permission.