How to install the paypal payment at Magento;
– go to System>Configuration>Payment Methods> Paypal Express checkout>Configure
– Insert Paypal Email address that is for the paypal account and select the API Signature for the API Authentication Methods. For the remain fields, you will use the “Get Credentials from Paypa” button that will open new popup window as below;
Then, add your email address and password. Then click the login. After that, it will show all other attributes such as, API user name,Password, and API signature. All you have to do is just copy and paste the values to the configuration fields.
– By testing on paypal processing, you will encounter to have an error that is “Unable to communicate with the PayPal gateway”. Then, most of cases, you have to disable the SSL verification at the advanced Settings.