The ability to manually add an employee is no longer available in QuickBooks Online with Payroll. It has been transitioned to the Employee Self Setup feature to improve speed, accuracy, and payroll compliance.
However, as a workaround, you can still enter their details manually. Here's how:
Navigate to the All apps menu, select Employees under the Payroll dropdown.
Click Start Employee Self Setup, fill in the necessary fields, and enter a dummy email address or your own email address (so it only sends the invite to yourself to start employee self setup, not to them).
Untick the Send reminder every _ days box.
Once done, click Save.
After saving, click the employee's name under the Employees tab, then enter their remaining details manually by following the on-screen instructions. You can also replace the dummy email with the employee's actual email address for your records.