Follow this step-by-step guide to granting the required developer access to your PayPal account for the purpose of processing online payments on your behalf. 

1. Log in to PayPal with your Personal or Business account. If you do not have an account, create one.

2. Click Profile at the top right, and select Profile and Settings.

3. In the left menu, click Selling tools.

4. In the Selling online section, click Update next to API access.

5. On the API Access page, click View API Signature.

6. On the next page, click Show against the fields API username, API password, API signature and send (copy & paste) these details to mypreorder (via a new support ticket).