Apple could not take my payment

Update your payment method with Apple. These are Apple's steps:

1. In Settings, tap your name.
2. Tap Payment & Shipping. You might be asked to sign in to your Apple Account.
3. Tap the payment method, then tap Edit. Enter the new details, then tap Done.

Once Apple takes the payment, the subscription goes on. Your diary is safe in the meantime. Apple's page: Change your Apple Account payment method.