Installation of Iperf

Hi everybody,
i have another problem. I want to measure the performance of my router Turris Omnia.
I´m in my SSH but when i write the iperf command is not working. Did i need to install iperf on my router? How can i archieve that?

Thank you for help

Go to LuCI in web browser. System > Software > Filter: iperf > Find package > Available packages > Install

There you go.

Or here: