How do I check the balance of an Everything Apple gift card?

Go to this link Check your gift card balance - Apple Support

Need to check to see if apple gift card has been used

go to the link in my previous response.

I purchased at the post office 3 $100.00 Apple Gift Cards for all things Apple. Two of them have errors. Can I get a refund at the post office or 2 new cards.

I need to know the balance of my All things Apple gift cards. How do I do that?

Go to the link I provided earlier