Hi @toadily369,
Welcome to the Community. l'm here to provide clarification on customization options for Profit and Loss Statements.
The option of customizing a Profit and Loss Statement to include the Period Comparison section is available in QuickBooks Online Essentials and Plus. One alternative that you may wish to consider is running a Profit and Loss Comparison Report, which will contain much of the same information and is available in Simple Start.
I'm including an article with additional information on the available reports in each version of QuickBooks Online: Report Comparison Between QuickBooks Online Subscriptions.
Please don't hesitate to post any questions that you may have. Cheers to a productive and prosperous day.