The EVKIT board has components that convert USB audio to I2S format to interface with the MAX98090. These components are unidirectional and can convert USB audio to I2S, but not the other way around. Because of this, the MAX98090EVKIT does not support recording audio from the board to a PC.
In order to record audio from the MAX98090 to a PC, you can use a MAXAUDINT001 board that you can purchase from Maxim or a local vendor. The MAXAUDINT001 board acts as the portion of the EVKIT that handles I2C, USB and SPDIF interfaces to program and use the CODEC with bi-directional USB audio. Use this new board to bypass the on-board USB to I2S transceiver (U200) at the jumper pins (JU15-16) with the USB audio transceiver on the MAXAUDINT001. This will allow you to record audio from the MAX98090 to the PC.