fastboot does not discover my device
fastboot is just one of the protocols to talk to the bootloader. Some manufacturers choose to support it (e.g. Google, HTC), others choose to make their bootloaders talk some other protocol (e.g. Samsung).

After googling a little bit, I don’t think that the bootloader of your device supports fastboot (at least, there are no mentions of this). Most likely, you will need a special tool from your manufacturer that will be able to talk to your device in bootloader mode.