I'll help you provide the details to update your bill subscription in QuickBooks Online (QBO), @mehryar.
If you have access to your email account, you can receive the code in your email account that you added to your QuickBooks account. However, if you still don't have access to the email, I suggest contacting our support team if you can't go through. They have all the necessary expertise and tools to assist you thoroughly with your important information. Here's how:
After that, you can upgrade to another plan. You can also check out this comparison chart to review what will go away when you switch. To change your plan, please follow the steps below:
To learn more on how to manage your QuickBooks Online Subscription, please refer to this article: Manage billing, payment, and subscription info in QuickBooks Online.
Additionally, you can check out this article to learn how to track bills and record payments: Enter and manage bills and bill payments in QuickBooks Online.
If you have further questions about updating your subscriptions, please don't hesitate to leave a reply in the comment section. We're always here to lend a hand. Have a great day.