First things first welcome back to the pack! Before you start your new subscription you will want to make sure your billing address and card number are correct. To do so you can visit here.
How to re-activate your poop bag subscription and add a new discount code:
Sign in to your account
Go to Account Details>Manage Subscriptions
Find your previous subscription
Click re-activate
Once you've re-activated your subscription you'll want to add the discount code you were given if applicable.
Add discount code and click save
Log out of your account when done
You can also watch this helpful video:
Choosing a selection results in a full page refresh.