You can update the payment information for your subscription through your company's Account and Settings. I'm here to ensure you're able to change your debit card info and enter your new account number.
Before we start, please note that you can only update your payment info using a web browser. But, if you subscribed to QuickBooks Online through an app store, you can update it through the app store directly.
Go to the Gear icon.
Select Account and Settings.
Choose Billing & Subscription.
Click the Pencil icon beside your payment method.
Update your credit card info.
Make sure the address in QuickBooks is the same as the one on your credit card statement.
Select Confirm card or Save.
Please let me know if you have other concerns. I'm just around to help.