Smart poteniometer?

Ok, I hadn’t known of the distinction!
In that case I think you need to use the VFD input and connect it using a PWM to voltage driver.
This was done in this posting, but there is no circuit diagram of the PWM to V.

But it seems that there is a device available for this:

I see it available locally to me for 7.10 EUR (inc VAT).
Perhaps this helps!