Renewing with Wallet Fund question

Hi. I took advantage and purchased the $80 gift card for $60 to cover my FB Plus renewal coming due at the end of January (thank you again for that offer)! I have the box checked to use wallet funds but do I need to also click the "apply wallet funds" button now or will that automatically happen on my renewal date? Based on earlier posts, this may be a question for Kelli's sister. :)