Welcome to the Forum Anna.
iClone 5 is a rather old version and while there was a Plugin available for that version I don't believe that it is still being sold by Reallusion. Since it was released 6 years ago I also doubt that it would work with any new hardware, or new Windows version.
Here's a link to the rather
old post announcing the plugin for iClone 5.
iClone 6, and 7 when it is released, now uses the Perception Neuron Mocap system - and it isn't cheap.
There is a lot of information on the use of the Perception Neuron system within iClone here.
Gerry
System: Win 10 Pro (21H2), Asus X99-E WS, CPU i7-5930K -3,5 GHz, 32 GB DDR4 2666-16 RAM, NVidia GTX 1080 Ti GPU - 11 GB VRAM(Driver Studio-536.99), Samsung 850 Pro 512 GB SSD, 6 TB HD storage.