If you are not getting resistance changes when using FulGaz for Windows 10, it may be that your smart trainer is not connecting via the correct channels.
Please ensure your trainer is NOT connected to any other apps or devices, reboot everything (power off from wall for a minute) and then select an option for both trainer resistance control AND power on the device pairing screen of FulGaz.
Pair your smart trainer as both trainer control AND power.
If using ANT+ to connect, please try repositioning your ANT+ dongle for a cleaner signal and/or moving the receiver closer to the trainer (within 50cm). Ideally, connect via Bluetooth if possible.