Welcome to the FOG Always good to put your country of origin in for website links etc.
What size port did you buy for your Sawstop? A 4" to 2 1/2" adapter may be needed. Then you can use a 50mm hose from Festool, or something like a regular "shop vac" 2 1/2" hose, like a Ridgid from Home Depot in the USA. They will fit right into your Midi.
Edit: Are you running a full size dust collector with a 4" port connected to the saw cabinet? Ideally a second 4" port with a gate valve would tie into the blade guard.
My Industrial came with the overarm blade guard and a 4” port. The 4” port had a 90 degree T port that the hose to the overarm attached to. That worked poorly. I just attached the new Mini’s hose to the overarm. Works perfectly. I did rig up a system the turns in the Mini when the saw starts. The Mini runs for about 10 seconds after the saw stops.
just for clarification, I was connection to the jobsite saw and that dust collection port site is smaller. For my contractors saw, I used a traditional dust collection hose from my Jet.