As long as the total power draw of the items plugged into the power strip is under 1800 watts (which it would be if you already have them plugged into a standard 15A North American wall outlet), you can plug a power strip into a Currant Smart Outlet.
Currant monitors each of the two outlets on the Smart Outlet separately. If a power strip is plugged into one of the outlets on the Currant Smart Outlet, the energy monitoring, and any rules you set up to control your devices, will apply to the entire power strip, and not the individual items plugged into it.
The Currant Smart Outlet does not disaggregate the electrical load across--and discern the device-level load of each electrical item that is plugged into--a power strip.
Please read the SAFETY section of the printed guidance located on the inside of the packaging sleeve in which you received your Currant Smart Outlet.