Thanks for checking out the Community, billing-websites.
The option to set u[ recurring transactions is only available in QuickBooks Online Essentials and Plus. If you're using the Simple Start version, you'll want to consider upgrading your plan so you'll be able to use this feature.
Once you're all set up and ready, feel free to browse the articles below to learn how to create, schedule, and manage your recurring transactions in QBO:
Keep me posted if you have any other concerns or additional questions. Have a great rest of the day.