Delete Me does not have access to third-party applications that offer subscriptions in your store; therefore, Delete Me cannot know whether a customer being deleted is subscribed to any application or not.
To prevent customers from deleting their account while their subscription is active, it is necessary to implement a front-end validation that blocks account deletion.
By registering with the webhook, you can notify the subscription app that the subscription needs to be canceled before the account can be deleted.
Additionally, you can tag customers with active subscriptions and specify this in the Delete Me settings screen to prevent account deletion (see the diagram below for reference).
If a customer wishes to cancel their subscription, please use the webhook. Using this, account deletion will then be possible.
From the Shopify admin panel, go to Online Store > Themes > Customize > Theme Settings > DELETE ME. Under the option "Customer has not been deleted (Failed, customer is subscribed)", you can set the message that will be displayed when a customer with an active subscription attempts to delete their account.
When the unsubscribe button is clicked, the following message will be displayed.