Nebula DG Charged $49.99 on MoneyLion Card

I recently discovered a charge of $49.99 on my MoneyLion debit card (last digits 48763) on May 2 for a Nebula DG subscription that I never subscribed to and that I was not even aware of. I do not know what this service is, I never agreed to any subscription, and I did not knowingly authorize this payment. Since I only use an iPhone, I suspect this may have been processed via the Apple App Store, but I have no clear information about how this subscription was started. I contacted my bank, MoneyLion, regarding this unauthorized charge, and they informed me that I would need to obtain a refund directly from Nebula. I am very uncomfortable with being charged for a service I did not request and cannot even identify, and I am concerned that similar charges could occur again without my consent. I kindly request that Nebula DG immediately cancel any subscription or account that may have been opened in my name or linked to my card and provide a full refund of the $49.99 to my MoneyLion debit card. I also ask for written confirmation that the subscription has been cancelled, that no further charges will be made, and, if possible, information on how this subscription was created without my explicit consent.