You can only downgrade your subscription if you currently have an active QuickBooks Online account, Realist.
Given that your QuickBooks Online subscription has expired, you will need to resubscribe first to reactivate your account before you can downgrade to the Plus plan. This step is necessary before making any changes to your subscription.
When resubscribing, ensure that you select the same billing frequency that you had with your previous subscription. Once done, you'll be able to recover your access to your subscription settings and can now downgrade from Advanced to Plus.
From there, you'll be prompted to make a call for further guidance since this plan includes many features that aren't available on the others.
Rest assured, you will not be charged immediately upon resubscribing. QuickBooks processes all account billing overnight, so any charges will not occur at midnight.
For example, if you resubscribe on July 8, 2025, any charges will not be applied immediately; they will process overnight and will reflect on July 9, 2025.
I'll also add this article in case you want to adjust your billing frequency if desired: Manage billing, payment, and subscription.
Feel free to reply to this post if you need further assistance.