Automatic invoicing may provide greater accuracy by utilizing preconfigured templates that include the correct data every time invoices are sent to your clients. At the moment, the option is only available when using you're using QuickBooks Online (QBO), mfitz3.
You can continue sending invoices to your clients manually. Another option is to upgrade your QuickBooks plan to QuickBooks Online if you want to avail the automation feature. I've added this link for you: Get Started with QuickBooks Online.
In case you decided to keep Solopreneur for your business, learn how you can record invoice payments: Record Invoice Payments.
To know more on what are the changes once you switch to QBO, I've added this for you: Learn What Changes When You Upgrade from QuickBooks Solopreneur to other QuickBooks Online Editions.
If you have any other questions or concerns when sending invoices, let me know so we can keep in touch. We're always here ready to assist you anytime.