To check your remaining class credits, log in to your account on the studio, gym or business website, go to your Profile and click on Memberships.

Find the active membership in question and you can see how many classes you have used and how many left. In the example below this member has used 7 out of 8 credits and has one remaining.

Depending on the type of membership or pack that your gym/studio/business has set up, it is also possible to re-purchase an expired one-time membership, clicking on the 3 dots by the membership/pack price will show - as in the example below, a Buy again button to repurchase.