The minimote must be on the same Zwave network as your hub and the two switches or you won’t be able to create the association.
The reason they’re hard to find now is that they will only work with older devices, not Z wave plus devices. That’s because the whole nature of association changed with zwave plus and Minimote is not able to set associations except for group one. So the minimote device has been discontinued.
FAQ: How zwave direct association changed with zwave plus
But as long as you have the older switches and the older hub, the minimote should work. Here is the old FAQ on how that works:
FAQ: Solution for Linear/GoControl 3-way switches? (WD500Z-1 and WT00Z-1) (Association options)
However, that is all off-topic for this particular thread, which is about the Z wave Tweaker. Please start a new thread to discuss any issues with the minimote. 