I downloaded the firmware file and followed instructions as explained at
https://support.klipsch.com/hc/en-us/articles/360034989111-The-Three-Firmware-Update
When I plug power in no LED's flash on the unit like it should. I left USB stick in for 10 minutes before taking it out. USB stick was hot.
Tried it with another USB stick with the same result, no flashing LEDs.
My app do not want to connect, thus I cannot update firmware via app and usb is not working.