The output of the Magic Sing ET23 system is designed as a consumer device, connecting to pro audio gear may require different cabling and a little patience.
The ET23 has a 3.5mm audio output connector that then can be fed into the StudioLive Mixers through the RCA Tape Inputs, or through the 3.5mm jack on the StudioLive AR series mixers. To use with any of the interfaces, you will need to get a 3.5mm to 1/4" Y Cable to be fed into the microphone or line level preamps.