ADAU1701 set digital signal input from the MP1, DAC3 output, why no sound output?

When pin MP1 is set to SDATA_IN1, its stereo signals will be on serial data input channels 2 and 3. The SDATA_IN0 signals will be on inputs 0 and 1.

In your SigmaStudio design, the ADC inputs are the top two pins of the input block (labeled 0 and 1) and the bottom 8 pins are the serial data channels. So, if your data is input on SDATA_IN1, then serial data channels 2 and 3 will appear in the SigmaStudio input block pins number 4 and 5. So, if you move your wire from pin 1 to pin 4, you should hear audio output on DAC3.

This is how the signal flow should look in SigmaStudio:

Thanks for your answer.