CFF quarterly bonus - am I doing it right?

I just got the CFF a couple weeks ago. The card took about a week to be able to add to PayPal and use it as PayPal’s default payment method when paying with PayPal. so I was just able to add and use it at checkout about 2 days ago. Question is, will I get 8% cash back using PayPal at a pharmacy if I only buy and load up on gift cards? Is that a thing? If so, does the transaction have to be pending or posted before the 31st?