You can set the input for DIG for either mono input or TRS stereo input. The pedal ships in mono configuration from the factory. Here’s how to adjust this configuration.
Remove the back cover of your pedal.
On the left side of the circuit board, you’ll see a jumper that can be set in two positions. Place the jumper on the left 2 pins for TRS stereo input. Place the jumper on the right 2 pins for mono input (factory setting).
In order to use the TRS stereo input, you’ll need a TRS stereo input adapter like the one shown below. You can purchase one here.