Currently, it's not possible to transfer subscriptions across different Apple IDs. Each subscription is linked to a specific account. Therefore, you're welcome to cancel your ongoing subscription and re-subscribe using your new Apple ID. To cancel your subscription, simply follow these steps:
- Open your device's Settings ⚙️
- Tap your name
- Tap Subscriptions
- Tap the subscription that you want to cancel
- Scroll down and tap Cancel Subscription
For further information on your subscription, we recommend you refer to Apple Support: they'd be happy to help you out.