We can turn off the Automatic Invoice reminders by going to the Gear icon in QuickBooks Online (QBO), Vikki. I'd be glad to guide you through the process.
If you're using QBO Simple Start, Essentials, or Plus, you can disable the feature from the Sales tab's Reminders section. Here's how:
- Go to the Gear icon and click Account and settings.

- Choose the Sales tab.
- From the Reminders section, toggle off the Automatic invoice reminders.

- Hit Save, then Done.
Check out this article for more details: Send invoice reminders automatically or manually in QuickBooks Online.
If you're using the Advanced version of QuickBooks, you can turn it off from your Workflows. Refer to the process below for your guide.

You can refer to this article for more information: Use workflows to automate your business processes for QuickBooks Online Advanced or Intuit Enterpris....
I'll attach some articles that can help you in managing your invoices and other sales forms:
Need help organizing transactions and managing finances? Partner with our QuickBooks Live Expert Assisted team for tailored advice. They offer personalized support, including help with setup, bookkeeping, transaction organization, and financial management.
Following the steps above will help you achieve your goal, Vikki. If you have more questions about managing your invoices in QuickBooks, just leave a reply below, and I'll assist you further.