You can easily add a new subscription plan to a subscription group.
In Ongoing App:
Make sure you already created a subscription group
Click on Subscription Groups
3. Choose the subscription group you want to add a subscription plan to
4. On the Plans tab, click Add Plan
5. Fill out the information for your new subscription plan. Click Add New Plan.
For example, I added a new subscription plan and this is what it looks like.
Now that you've created a subscription plan, make sure to add a product!