You’ll need to establish how that unit expects the TRS to be wired - there’s (at least) 2 different ways to wire MIDI to TRS, typically on 3.5mm, but also on 2.5mm, but not generally to 6.25mm as you’ll require
The simplest route (besides making your own, quite easy with a solder iron and a wired midi cable to butcher) will be to source one by Korg or Arturia or similar depending on the different wiring possibilities and get a simple adaptor to transition (probably) 3.5mm to 6.25mm
e.g. with cheap stuff like this you have no guarantee it’ll last or that the correct pins are used in the DIN plug
Having said all that - there seems to be full size TRS adaptor cables shown for sale here - so do your research on these
good stuff - as long as you’re happy with the research - worst case is you’ll need to ask someone to re-solder the wires in the TRS
maybe you need a longer cable than that, so perhaps having a breakout cable, is more convenient (a female midi socket) - the listings here convey the number of permutations you may need to be mindful about unless there’s a standard approach for most pedals with larger TRS
Thank you very much dear. I’ve in Paris near my home some guys who make this kind of things, maybe I will ask them some indication about the soldering or to make one for me.
If not I will properly do that from myself, So many times I think about little “primo microphone DIY” “Piezo FX box DIY” etc. It’s now a new reason to process…
Internet is so great for that.
Good weed Sir !