1. Log in to your PayPal Business account.
2. Click the My Account tab.
3. Click the Profile tab. If you haven’t already done so, you need to verify your account before requesting API credentials.
4. Click Request API credentials under Account information.
5. Click Set up PayPal API credentials and permissions under Option 1.
6. Click Request API Credentials.
7. Click Request API signature.
8. Click Agree and Submit.
9. Copy and paste the API username, password, and signature into your site.