In order to accept payment via PayPal you need:

  1. Create and configure REST API application on PayPal developer site. For more information please read Manage your applications.
  2. Add payment processor on Sippy Softswitch. Use PayPal REST API (PayPal) payment gateway to accept PayPal payments and PayPal REST API (Credit Cards) to accept payments by credit cards.
  3. Configure API Credentials - the sandbox (Test) or live (Production) account Client ID and Secret used to make API calls:

Here are the screenshots of the pages (taken from PayPal portal on Jul 6, 2018) where you can get Client ID and Secret: