There are two ways to enter your Sandbox credentials (test credentials) into your website for order testing prior to officially launching your new website.
1. Log in to your website using administrator credentials.
2. On the left sidebar, navigate to Woocommerce > Settings.
3. On the Payment tab, scroll down to ‘Environment’ and change to Sandbox.
4. Click the ‘Setup or link an existing Paypal Sandbox Account’ and log in with your Paypal account information.
To manually enter test credentials:
1. Log in to the PayPal sandbox at www.sandbox.paypal.com.
2. Click the settings icon at the top of your PayPal account page and then click Account Settings.
3. On the Account access page, click Update for the API access item.
4. Click Manage API Credentials in the NVP/SOAP API Integration (Classic) section.
5. Select Request API signature. Then, click Agree and Submit.