Updated instructions for PayPal Complete Payments.
Log into your PayPal account then go to Account Settings -> Website Payments (link).
Next click Update next to API Access. (link)
On the next screen, click the REST API Integrations.
If you haven't created an App before, there should be a default one. Click on the name of the default app under Apps.
This is a plain text area where you can enter in any text. Mouse over to edit.
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