You sure can!
All cards that offer this feature have a "Points" section available in your card screen.
Before you can access your points via Stocard, please make sure that your card account has already been activated on the respective card provider's homepage or app. The login credentials you choose there will then also be your login credentials to access this particular points account via Stocard.
If your card does not show a "Points" section, this means that this feature is not available for this particular card yet. However, please always feel free to send us your suggestions for cards where you would like to see your points balance to firstname.lastname@example.org and we will try to make this possible in the future.