No, you do not need to be a member to use or purchase Academy credits.
The whole point of credits is now members or
non-members can purchase credits to access any
lesson or class. This allows you to create a program that works best for you. For example, if you are someone who is not interested in a membership, or you're on a budget, you can purchase Academy credits to access the material without needing a full membership.
With that said, the benefit of a membership
is that with a membership you can access all of the lessons, classes or coaching sessions (depending on the membership you purchase).