While waiting for the response coming from our new member, @gdc, I've you the ways on how QuickBooks works with manual payroll entry.
To start with, you can create a journal entry to start recording your manual paychecks. See this article for more insights: Create a journal entry.
On that same page, you still need to have an active payroll subscription so that QuickBooks can report and calculate your taxes accurately.
That being said, here's an article you can read to learn more about how the manual payroll works: Manually enter payroll paychecks in QuickBooks Online.
Keep me posted in the comment section down below if you have any other questions. I'm always around happy to lend a helping hand.