The DigiOne is an I2S device. Look down the list and near the top you will find 'Allo DigiOne Signature'. Set it and reboot as instructed. Your Chord Mojo should be connected to the Sig by SPDIF.
Edit: You will need an RCA to 3.5mm jack cable for the connection.
Edit: You will need an RCA to 3.5mm jack cable for the connection.