Set feedback gain to "0", Wet/Dry to "100 (Wet)", all filters in the second page to "Thru", and High Ratio to "1.0". This gives you simply delayed audio output.
Assignment from input channels should be "POST" and at nominal ("0"). And make sure Pan Link for the stereo aux bus is turned on. (System Setup -> Bus Setup) Then, mixing balance will be same as the STEREO main bus.
The example above shows 30msec which gives signal delay for about 30ft (10m).
Please be aware of master output level of the system. Master fader for STEREO mains and the stereo aux are independent. For example, to boost system SPL by 3dB, you will push the STEREO master up by 3dB and the stereo aux master by 3dB. Or, create a DCA group for all input to change the level from one place.
This example can be found in Scene A98 for your reference.