Simply run the output of the Eureka to the Line Input of the mixer, using either TRS to TRS or XLR to TRS. Line Inputs do not run through the Preamp Section, but through a Line Amplifier direct to the A/D chip. Use the input / output controls on the Eureka first to gain stage, then use the mixer to add whatever additional gain you need.
Set the device up in your DAW using the instructions from the Software Manual on our Downloads Page for the product you are using.