Note: Our current 'subscriptions' feature is an order reminder, and re-order system, built into the app. This pre-dates the availability of a subscription API, which allows for automatic recurring billing within Shopify. However, this API has now become available, allowing us to work on adding this into the app.
After communication with Shopify, and in line with our plans to extend Bundle Builder's functionality and add in true subscriptions, including automatic recurring billing, in the near future - we are removing what we currently label as 'subscriptions' from the app, for all new app installs, and merchants who do not currently have active subscriptions set on current bundles.
We are currently working on a revamped Bundle Builder, due for release in phases throughout 2022.
This will have no impact on any current bundles, which offer 'subscriptions'.
Subscription apps cannot be currently integrated with Bundle Builder. Recurring payment apps (like Assemble, Recharge, or Paywhirl) - or other subscription service based apps - have conflicting code, which prevents Bundle Builder from operating correctly.
As a workaround, Bundle Builder offers inbuilt functionality which supports subscriptions for bundles created - for more information, see Purchase Options & Subscriptions.
Currently, it is not yet possible to integrate third party apps for this purpose.
Read: For further information about why Bundle Builder can't integrate with subscription apps, click here to read Shopify's guide on known limitations.