Flux depends on CUDA.jl by default for GPU acceleration, so using Flux will always try to find and load GPU-related functionality. On a machine without nvidia drivers installed (e.g. your netbook), this will fail gracefully and not attempt to run any more CUDA-specific code. Think of it as the “CPU-only” mode.
When your machine does have nvidia drivers installed (presumably because there’s an nvidia GPU attached to it), CUDA.jl will try to download and run an appropriate SDK based on your current driver version. I’m not sure what the minimal driver version is, but 390.132 is definitely too old (nvidia-smi reports 450.51.06 on my system). Can you update your driver at all? Assuming your GPU is supported on a relatively recent one, Flux + CUDA should work OOTB.