Unable to issue a refund.

[Dave19]

To issue a refund, info is as follows:

To issue a refund:
Go to Activity.
Find the payment you'd like to refund.
Select the payment to open the details.
Click Refund this payment.

The first 2 steps work fine.

There is nothing available to click on to activate the 'Refund' button.

Would appreciate any assistance.

Dave19