How to Sign in with Apple and redeem Gift card

Hi, I downloaded candy crush on my iPhone I used the sign in with Apple iOS to play my game. I have a virtual Candy Crush Gift Card. I understand I can still redeem it with a Apple iOS sign-in but to do is I have to make an email account. I have the email, but what do I do to redeem my card to continue with my game already in process.

When I sign into my game with Apple, I'm at level 200. I log out then sign in with my email address but it starts off as a brand new game at level 1.

How do I get my Candy Crush Gift Card with my email address to my game already in progress game at level 200 without losing my progress?

I done this just before with another Candy Crush Gift Card and I entered my pin and it just gave my a brand new game starting up with my card. I wasted my card.

I don't want to make a mistake on this card. How do I do it?