Thanks for the quick reply. The discount is applied on the PayPal checkout screen now.
There was however this bit of extraneous code on the "order received" page I returned to after making the test purchase.
array(0) { }
In addition to this code, the "Gift Card Amount" showed as $0 even though the gift card I created was for $100. When I checked for the balance of the gift card from the Wordpress admin area, it was still at $100, too (as if it had never been used).
Once I marked the order as "complete" in the "Orders" section of the WooCommerce admin area, the balance of the gift card went to $0, the "Order Received" page indicated the "Gift Card Amount" was $100 (instead of $0 as before) and the extraneous bit of code I mentioned earlier disappeared.
Was this supposed to happen this way or was the balance of the gift card supposed to update automatically? I'm just asking because I'm wrapping up a store for a client and want to be sure I advise them properly.