Use this thought to get you going - proceed at your own risk and do some research, yhbw - shame to ruin what looks like a great pedal
Your trying to mimic what the device would detect if you connected an FS3x and pressed the various buttons
The delay will send out voltage(s?) through the tip and ring, so if you could establish this from a voltmeter you’d be able to know the level you’re needing to set for two of the footswitch functions, the third option looks like it will be both of these voltages simultaneously
I’m not sure if the pedal is a latched or toggled arrangement, in which case it may dictate whether you put in a sustained voltage or a voltage blip
But if you decide it’s safe to proceed with sending voltage to the TRS jack, start on one signal to begin with - e.g. tip - set up a value Lin or gate or trig or any voltage you can set to step up on demand and set the voltage range low to begin with, cycle the sequencer, and manually raise the voltage until the expected (1 of 3) effect occurs - this may well be in the 3-5V range, but start at 1v and proceed carefully
Say the voltage needs to be 3V, then for function 1 - make the voltage blip or sustain 3v (depending on expected footswitch type) on A4tip, do the same for A4ring and do both simultaneously (tip and ring) for the third function - doing this on one track with p-locks on Value Lin is simplest
Google will help if you broaden the search to other devices using a three button similar footswitch - or ask DOD what voltage to send if you can’t measure it - if you have another CV synth, you’d be able to send the voltage to the synth from the pedal if you had a Y splitter (like the Elektron one) and deduce what the voltage was - only do so if you know the input to a synth can handle a potentially high voltage but I doubt it’ll be higher than suggested
If in doubt - ask maker - use above as a methodical way to get the ball rolling if you’re confident you follow and can set A4 up