Knowledgebase

To enable PayPal Express Checkout, you will need to get/generate your api signature along with username and password.
Login to your account then navigate My Account > Profile > My Selling Preferences
Within the selling online section locate API access and then click on the corresponding update link.

You need to use option 2 Request API credentials
Click on the View/Generate API Signature link

You should see something like the above example, you will need to copy the values you have in your account to the appropriate payment page settings as these values are just examples and are not valid.