Hi and welcome.
The Audiofuse does not have built-in amplification.
It is designed to be connected to speakers with built in amplifiers, called powered or active speakers.
There is a difference between powered speakers and active speakers but mainly you just need to take away the fact they have built in amplifiers.
Most domestic hifi speakers do not have built in amplifiers, therefore you need to provide one.
To use the Audiofuse with domestic hifi speakers you would need a stereo cable from the Audiofuse speakers A or B outputs into the line input of a separate stereo amplifier, to which you would then connect your hifi speakers.
Set the volume output on the Audiofuse to about midway so as not to overload the input on the amplifier.