Hey Henrik,
the Onefinity Controller offers PWM output that you get at the corresponding pin and that is adjusted with the PWM settings on TOOL page. It is usually needed by PWM spindles.
Besides ModBus and Analog 0-10 V input, my VFD also has a PWM input. If your VFD has only analog 0-10 V voltage input but no PWM input, you need a PWM to voltage converter module. Take care to choose one that works with 3.3 V PWM input.