Let’s reactivate your employee, faogsec.
You'll get an error that an employee name already exists if you create a different profile.
Did you just move your files to QuickBooks Online? Usually, you won’t have an option to reactivate if you moved from a different platform, and you haven’t run payroll in QBO yet. In this case, you can run a dummy payroll for an active employee and reactivate the terminated one. Then, you can delete the dummy payroll after.
Please let me know what happens after you do the steps I mentioned. We’re just right here to help you further.