3 Months Xbox Game Pass for $1 Deal Questions

Hey everyone!

I checked the FAQs for the 3 months Xbox Game Pass for $1 deal but unfortunately there was no answer to my question.

Here is the situation:

I haven't used xbox game pass ever on my account so I am a new subscriber. I have $5.94 in my account (from Microsoft rewards). When I click join for this deal, it says I need more than $1 to cover the costs for price after the 3 months are over. I click
on How do you want to pay the rest? button and I put in my credit card info. My question (before joining) is that will the $1+tax be charged on store credit or on my credit card? I do not want to pay $9.99/month after (I have an extra month code I want to
use the code after I have claimed this deal to have 4 months). I can and know how to cancel recurring payment.

:)