Facebook subscriber subscriptions are tricky for us here at GHScanner to manage; we really just can't manage them. We are not given the option to manage them.
To cancel a subscription on Facebook, go to Settings & Privacy > Orders and Payments > Subscriptions in the app and select the active subscription to cancel. Alternatively, for creator (Like ours) subscriptions, navigate to our page, select "Go to Subscriber Hub," and manage your subscription there.