Hey Amanda16,
When you click on Employees, do you see Payroll and Employees at the top of the screen? If so call 0808 234 5337 and request to be swapped our payroll software that supports CIS.
If you do not see payroll and employees at the top of the screen, you should see "powered by paysuite", in which case you can go into the Cog Wheel - Employer Settings - Real Time Information - Submit EPS.
Let us know what you see when you access payroll.