This is a simple question. I am using the Paypal php api (https://www.x.com/sites/default/files/merchant-php-2.0.96.zip). I found my api keys (Api username, password and signature). But I cannot find where to specify them in express check out in the PHP SDK( I am using the Express checkout from the Samples).
Any help is appreciated.
Modify this file config/sdk_config.ini