PayPal Express requires a PayPal Business Account. If you don't have a PayPal Business account, you can create a new PayPal Business account here.
To activate PayPal Express;
1. In your control panel click on Settings and then select Payment.
2. Click on Add Payment Gateway.
3. Choose Paypal Express from the Payment Gateway list.
4. Type your PayPal Business account’s email address to the Email section.
5. Click on the ADD button to save. That's all. :)
Note: If you don't have a PayPal Business account click here to create one.