Get your API test credentials
All PayPal API requests require API credentials to verify the call is being made through a valid PayPal account. Calls to the sandbox testing environment are no different but they require that you use the test credentials assigned to one of your sandbox Business accounts.
Tip: The PayPal sandbox and live environments each use different sets of API credentials. Use the correct set of credentials for the endpoints you're addressing.
View and manage your API credentials
Braintree SDK apps — Braintree SDK sandbox test credentials can be created and managed on the PayPal Developer site My Apps & Credentials page.
REST API apps — You can view and manage the REST API sandbox and live credentials on the PayPal Developer site My Apps & Credentials page. Within the setting for each of your apps, use the Sandbox or Live toggle in the top right corner of the app settings page to view the API credentials and default PayPal account for each of these environments. If you have not created an app, navigate to the My Apps & Credentials page.
The PayPal Developer site also assigns each sandbox Business account a set of test API credentials. Log in to the PayPal Developer site and navigate to the Sandbox Accounts page or Dashboard > Sandbox > Accounts. View your test API credentials by clicking the Manage Accounts icon next to the Business account that you want to use in your request, selecting View/Edit Account, and navigating to the API credentials tab.
NVP/SOAP API apps — You can view and manage the NVP/SOAP APIs (formerly Classic API) app credentials on the PayPal sandbox (see the api credentials page) or here. These APIs include Express Checkout, Website Payments Pro, Adaptive Payments, Adaptive Accounts, Mass Payments, the Button Manager API, the Permissions Service, and the SOAP version of the Invoicing Service.
Payflow Gateway & PayPal Payments Pro apps — You can manage the Payflow Gateway and PayPal Payments Pro API live and pilot app credentials on the PayPal Manager site. These APIs are typically tested through the Payflow pilot. However, if you're sending Express Checkout transactions through Payflow, you can use the PayPal sandbox for testing. For more information, see Testing your PayPal Payments Advanced and PayPal Payments Pro integration.